diff --git a/.travis.yml b/.travis.yml
index 406d585..35e8b9b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,8 +1,12 @@
 language: elixir
 elixir:
-  - 1.4
+  - 1.8
+otp_release:
+  - 21.0
 env:
   - MIX_ENV=test
+services: # ensure that Travis-CI provisions a DB for our tests
+  - postgresql
 script:
   - mix do deps.get, compile, coveralls.json
 after_success:
diff --git a/mix.exs b/mix.exs
index 018d361..7232347 100644
--- a/mix.exs
+++ b/mix.exs
@@ -12,7 +12,7 @@ defmodule Library.Mixfile do
       aliases: aliases(),
       deps: deps(),
       test_coverage: [tool: ExCoveralls],
-      preferred_cli_env: ["coveralls": :test, "coveralls.detail": :test, "coveralls.post": :test, "coveralls.html": :test]
+      preferred_cli_env: [coveralls: :test, "coveralls.detail": :test, "coveralls.post": :test, "coveralls.html": :test]
     ]
   end
 
@@ -46,7 +46,7 @@ defmodule Library.Mixfile do
       {:pre_commit, "~> 0.1.4"},
       {:elixir_auth_github, "~> 0.1.4"},
       {:envy, "~> 1.1.1"},
-      {:credo, "~> 0.8", only: [:dev, :test], runtime: false},
+      {:credo, "~> 1.1.0", only: [:dev, :test], runtime: false},
       {:excoveralls, "~> 0.7", only: :test}
     ]
   end
@@ -61,7 +61,7 @@ defmodule Library.Mixfile do
     [
       "ecto.setup": ["ecto.create", "ecto.migrate", "run priv/repo/seeds.exs"],
       "ecto.reset": ["ecto.drop", "ecto.setup"],
-      "test": ["ecto.create --quiet", "ecto.migrate", "test"]
+      test: ["ecto.create --quiet", "ecto.migrate", "test"]
     ]
   end
 end
diff --git a/mix.lock b/mix.lock
index 8415246..868d7e4 100644
--- a/mix.lock
+++ b/mix.lock
@@ -1,35 +1,40 @@
-%{"bunt": {:hex, :bunt, "0.2.0", "951c6e801e8b1d2cbe58ebbd3e616a869061ddadcc4863d0a2182541acae9a38", [:mix], [], "hexpm"},
-  "certifi": {:hex, :certifi, "2.0.0", "a0c0e475107135f76b8c1d5bc7efb33cd3815cb3cf3dea7aefdd174dabead064", [:rebar3], [], "hexpm"},
+%{
+  "bunt": {:hex, :bunt, "0.2.0", "951c6e801e8b1d2cbe58ebbd3e616a869061ddadcc4863d0a2182541acae9a38", [:mix], [], "hexpm"},
+  "certifi": {:hex, :certifi, "2.5.1", "867ce347f7c7d78563450a18a6a28a8090331e77fa02380b4a21962a65d36ee5", [:rebar3], [{:parse_trans, "~>3.3", [hex: :parse_trans, repo: "hexpm", optional: false]}], "hexpm"},
   "connection": {:hex, :connection, "1.0.4", "a1cae72211f0eef17705aaededacac3eb30e6625b04a6117c1b2db6ace7d5976", [:mix], [], "hexpm"},
   "cowboy": {:hex, :cowboy, "1.1.2", "61ac29ea970389a88eca5a65601460162d370a70018afe6f949a29dca91f3bb0", [:rebar3], [{:cowlib, "~> 1.0.2", [hex: :cowlib, repo: "hexpm", optional: false]}, {:ranch, "~> 1.3.2", [hex: :ranch, repo: "hexpm", optional: false]}], "hexpm"},
   "cowlib": {:hex, :cowlib, "1.0.2", "9d769a1d062c9c3ac753096f868ca121e2730b9a377de23dec0f7e08b1df84ee", [:make], [], "hexpm"},
-  "credo": {:hex, :credo, "0.8.8", "990e7844a8d06ebacd88744a55853a83b74270b8a8461c55a4d0334b8e1736c9", [:mix], [{:bunt, "~> 0.2.0", [hex: :bunt, repo: "hexpm", optional: false]}], "hexpm"},
-  "db_connection": {:hex, :db_connection, "1.1.2", "2865c2a4bae0714e2213a0ce60a1b12d76a6efba0c51fbda59c9ab8d1accc7a8", [:mix], [{:connection, "~> 1.0.2", [hex: :connection, repo: "hexpm", optional: false]}, {:poolboy, "~> 1.5", [hex: :poolboy, repo: "hexpm", optional: true]}, {:sbroker, "~> 1.0", [hex: :sbroker, repo: "hexpm", optional: true]}], "hexpm"},
-  "decimal": {:hex, :decimal, "1.4.1", "ad9e501edf7322f122f7fc151cce7c2a0c9ada96f2b0155b8a09a795c2029770", [:mix], [], "hexpm"},
-  "ecto": {:hex, :ecto, "2.2.6", "3fd1067661d6d64851a0d4db9acd9e884c00d2d1aa41cc09da687226cf894661", [:mix], [{:db_connection, "~> 1.1", [hex: :db_connection, repo: "hexpm", optional: true]}, {:decimal, "~> 1.2", [hex: :decimal, repo: "hexpm", optional: false]}, {:mariaex, "~> 0.8.0", [hex: :mariaex, repo: "hexpm", optional: true]}, {:poison, "~> 2.2 or ~> 3.0", [hex: :poison, repo: "hexpm", optional: true]}, {:poolboy, "~> 1.5", [hex: :poolboy, repo: "hexpm", optional: false]}, {:postgrex, "~> 0.13.0", [hex: :postgrex, repo: "hexpm", optional: true]}, {:sbroker, "~> 1.0", [hex: :sbroker, repo: "hexpm", optional: true]}], "hexpm"},
+  "credo": {:hex, :credo, "1.1.4", "c2f3b73c895d81d859cec7fcee7ffdb972c595fd8e85ab6f8c2adbf01cf7c29c", [:mix], [{:bunt, "~> 0.2.0", [hex: :bunt, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm"},
+  "db_connection": {:hex, :db_connection, "1.1.3", "89b30ca1ef0a3b469b1c779579590688561d586694a3ce8792985d4d7e575a61", [:mix], [{:connection, "~> 1.0.2", [hex: :connection, repo: "hexpm", optional: false]}, {:poolboy, "~> 1.5", [hex: :poolboy, repo: "hexpm", optional: true]}, {:sbroker, "~> 1.0", [hex: :sbroker, repo: "hexpm", optional: true]}], "hexpm"},
+  "decimal": {:hex, :decimal, "1.8.0", "ca462e0d885f09a1c5a342dbd7c1dcf27ea63548c65a65e67334f4b61803822e", [:mix], [], "hexpm"},
+  "ecto": {:hex, :ecto, "2.2.12", "ce7f619c1451daad0f59e8f01fd8e2584226171dc273e3346444446a13d93943", [:mix], [{:db_connection, "~> 1.1", [hex: :db_connection, repo: "hexpm", optional: true]}, {:decimal, "~> 1.2", [hex: :decimal, repo: "hexpm", optional: false]}, {:mariaex, "~> 0.8.0", [hex: :mariaex, repo: "hexpm", optional: true]}, {:poison, "~> 2.2 or ~> 3.0", [hex: :poison, repo: "hexpm", optional: true]}, {:poolboy, "~> 1.5", [hex: :poolboy, repo: "hexpm", optional: false]}, {:postgrex, "~> 0.13.0", [hex: :postgrex, repo: "hexpm", optional: true]}, {:sbroker, "~> 1.0", [hex: :sbroker, repo: "hexpm", optional: true]}], "hexpm"},
   "elixir_auth_github": {:hex, :elixir_auth_github, "0.1.4", "436b40bc4082e352c261e0bb62d547c62c4b68a45948f3ed5326699de492148a", [:mix], [{:httpoison, "~> 0.13", [hex: :httpoison, repo: "hexpm", optional: false]}, {:poison, "~> 3.1", [hex: :poison, repo: "hexpm", optional: false]}], "hexpm"},
   "envy": {:hex, :envy, "1.1.1", "0bc9bd654dec24fcdf203f7c5aa1b8f30620f12cfb28c589d5e9c38fe1b07475", [:mix], [], "hexpm"},
-  "excoveralls": {:hex, :excoveralls, "0.7.4", "3d84b2f15a0e593159f74b19f83794b464b34817183d27965bdc6c462de014f9", [:mix], [{:exjsx, ">= 3.0.0", [hex: :exjsx, repo: "hexpm", optional: false]}, {:hackney, ">= 0.12.0", [hex: :hackney, repo: "hexpm", optional: false]}], "hexpm"},
+  "excoveralls": {:hex, :excoveralls, "0.11.2", "0c6f2c8db7683b0caa9d490fb8125709c54580b4255ffa7ad35f3264b075a643", [:mix], [{:hackney, "~> 1.0", [hex: :hackney, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm"},
   "exjsx": {:hex, :exjsx, "4.0.0", "60548841e0212df401e38e63c0078ec57b33e7ea49b032c796ccad8cde794b5c", [:mix], [{:jsx, "~> 2.8.0", [hex: :jsx, repo: "hexpm", optional: false]}], "hexpm"},
-  "file_system": {:hex, :file_system, "0.2.2", "7f1e9de4746f4eb8a4ca8f2fbab582d84a4e40fa394cce7bfcb068b988625b06", [:mix], [], "hexpm"},
-  "gettext": {:hex, :gettext, "0.13.1", "5e0daf4e7636d771c4c71ad5f3f53ba09a9ae5c250e1ab9c42ba9edccc476263", [:mix], [], "hexpm"},
-  "hackney": {:hex, :hackney, "1.10.1", "c38d0ca52ea80254936a32c45bb7eb414e7a96a521b4ce76d00a69753b157f21", [:rebar3], [{:certifi, "2.0.0", [hex: :certifi, repo: "hexpm", optional: false]}, {:idna, "5.1.0", [hex: :idna, repo: "hexpm", optional: false]}, {:metrics, "1.0.1", [hex: :metrics, repo: "hexpm", optional: false]}, {:mimerl, "1.0.2", [hex: :mimerl, repo: "hexpm", optional: false]}, {:ssl_verify_fun, "1.1.1", [hex: :ssl_verify_fun, repo: "hexpm", optional: false]}], "hexpm"},
+  "file_system": {:hex, :file_system, "0.2.7", "e6f7f155970975789f26e77b8b8d8ab084c59844d8ecfaf58cbda31c494d14aa", [:mix], [], "hexpm"},
+  "gettext": {:hex, :gettext, "0.17.0", "abe21542c831887a2b16f4c94556db9c421ab301aee417b7c4fbde7fbdbe01ec", [:mix], [], "hexpm"},
+  "hackney": {:hex, :hackney, "1.15.2", "07e33c794f8f8964ee86cebec1a8ed88db5070e52e904b8f12209773c1036085", [:rebar3], [{:certifi, "2.5.1", [hex: :certifi, repo: "hexpm", optional: false]}, {:idna, "6.0.0", [hex: :idna, repo: "hexpm", optional: false]}, {:metrics, "1.0.1", [hex: :metrics, repo: "hexpm", optional: false]}, {:mimerl, "~>1.1", [hex: :mimerl, repo: "hexpm", optional: false]}, {:ssl_verify_fun, "1.1.5", [hex: :ssl_verify_fun, repo: "hexpm", optional: false]}], "hexpm"},
   "httpoison": {:hex, :httpoison, "0.13.0", "bfaf44d9f133a6599886720f3937a7699466d23bb0cd7a88b6ba011f53c6f562", [:mix], [{:hackney, "~> 1.8", [hex: :hackney, repo: "hexpm", optional: false]}], "hexpm"},
-  "idna": {:hex, :idna, "5.1.0", "d72b4effeb324ad5da3cab1767cb16b17939004e789d8c0ad5b70f3cea20c89a", [:rebar3], [{:unicode_util_compat, "0.3.1", [hex: :unicode_util_compat, repo: "hexpm", optional: false]}], "hexpm"},
+  "idna": {:hex, :idna, "6.0.0", "689c46cbcdf3524c44d5f3dde8001f364cd7608a99556d8fbd8239a5798d4c10", [:rebar3], [{:unicode_util_compat, "0.4.1", [hex: :unicode_util_compat, repo: "hexpm", optional: false]}], "hexpm"},
+  "jason": {:hex, :jason, "1.1.2", "b03dedea67a99223a2eaf9f1264ce37154564de899fd3d8b9a21b1a6fd64afe7", [:mix], [{:decimal, "~> 1.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm"},
   "jsx": {:hex, :jsx, "2.8.3", "a05252d381885240744d955fbe3cf810504eb2567164824e19303ea59eef62cf", [:mix, :rebar3], [], "hexpm"},
   "metrics": {:hex, :metrics, "1.0.1", "25f094dea2cda98213cecc3aeff09e940299d950904393b2a29d191c346a8486", [:rebar3], [], "hexpm"},
-  "mime": {:hex, :mime, "1.1.0", "01c1d6f4083d8aa5c7b8c246ade95139620ef8effb009edde934e0ec3b28090a", [:mix], [], "hexpm"},
-  "mimerl": {:hex, :mimerl, "1.0.2", "993f9b0e084083405ed8252b99460c4f0563e41729ab42d9074fd5e52439be88", [:rebar3], [], "hexpm"},
-  "phoenix": {:hex, :phoenix, "1.3.0", "1c01124caa1b4a7af46f2050ff11b267baa3edb441b45dbf243e979cd4c5891b", [:mix], [{:cowboy, "~> 1.0", [hex: :cowboy, repo: "hexpm", optional: true]}, {:phoenix_pubsub, "~> 1.0", [hex: :phoenix_pubsub, repo: "hexpm", optional: false]}, {:plug, "~> 1.3.3 or ~> 1.4", [hex: :plug, repo: "hexpm", optional: false]}, {:poison, "~> 2.2 or ~> 3.0", [hex: :poison, repo: "hexpm", optional: false]}], "hexpm"},
-  "phoenix_ecto": {:hex, :phoenix_ecto, "3.3.0", "702f6e164512853d29f9d20763493f2b3bcfcb44f118af2bc37bb95d0801b480", [:mix], [{:ecto, "~> 2.1", [hex: :ecto, repo: "hexpm", optional: false]}, {:phoenix_html, "~> 2.9", [hex: :phoenix_html, repo: "hexpm", optional: true]}, {:plug, "~> 1.0", [hex: :plug, repo: "hexpm", optional: false]}], "hexpm"},
-  "phoenix_html": {:hex, :phoenix_html, "2.10.4", "d4f99c32d5dc4918b531fdf163e1fd7cf20acdd7703f16f5d02d4db36de803b7", [:mix], [{:plug, "~> 1.0", [hex: :plug, repo: "hexpm", optional: false]}], "hexpm"},
-  "phoenix_live_reload": {:hex, :phoenix_live_reload, "1.1.3", "1d178429fc8950b12457d09c6afec247bfe1fcb6f36209e18fbb0221bdfe4d41", [:mix], [{:file_system, "~> 0.2.1 or ~> 0.3", [hex: :file_system, repo: "hexpm", optional: false]}, {:phoenix, "~> 1.0 or ~> 1.2 or ~> 1.3", [hex: :phoenix, repo: "hexpm", optional: false]}], "hexpm"},
-  "phoenix_pubsub": {:hex, :phoenix_pubsub, "1.0.2", "bfa7fd52788b5eaa09cb51ff9fcad1d9edfeb68251add458523f839392f034c1", [:mix], [], "hexpm"},
-  "plug": {:hex, :plug, "1.4.3", "236d77ce7bf3e3a2668dc0d32a9b6f1f9b1f05361019946aae49874904be4aed", [:mix], [{:cowboy, "~> 1.0.1 or ~> 1.1", [hex: :cowboy, repo: "hexpm", optional: true]}, {:mime, "~> 1.0", [hex: :mime, repo: "hexpm", optional: false]}], "hexpm"},
+  "mime": {:hex, :mime, "1.3.1", "30ce04ab3175b6ad0bdce0035cba77bba68b813d523d1aac73d9781b4d193cf8", [:mix], [], "hexpm"},
+  "mimerl": {:hex, :mimerl, "1.2.0", "67e2d3f571088d5cfd3e550c383094b47159f3eee8ffa08e64106cdf5e981be3", [:rebar3], [], "hexpm"},
+  "parse_trans": {:hex, :parse_trans, "3.3.0", "09765507a3c7590a784615cfd421d101aec25098d50b89d7aa1d66646bc571c1", [:rebar3], [], "hexpm"},
+  "phoenix": {:hex, :phoenix, "1.3.4", "aaa1b55e5523083a877bcbe9886d9ee180bf2c8754905323493c2ac325903dc5", [:mix], [{:cowboy, "~> 1.0", [hex: :cowboy, repo: "hexpm", optional: true]}, {:phoenix_pubsub, "~> 1.0", [hex: :phoenix_pubsub, repo: "hexpm", optional: false]}, {:plug, "~> 1.3.3 or ~> 1.4", [hex: :plug, repo: "hexpm", optional: false]}, {:poison, "~> 2.2 or ~> 3.0", [hex: :poison, repo: "hexpm", optional: false]}], "hexpm"},
+  "phoenix_ecto": {:hex, :phoenix_ecto, "3.6.0", "d65dbcedd6af568d8582dcd7da516c3051016bad51f9953e5337fea40bcd8a9d", [:mix], [{:ecto, "~> 2.2", [hex: :ecto, repo: "hexpm", optional: false]}, {:phoenix_html, "~> 2.9", [hex: :phoenix_html, repo: "hexpm", optional: true]}, {:plug, "~> 1.0", [hex: :plug, repo: "hexpm", optional: false]}], "hexpm"},
+  "phoenix_html": {:hex, :phoenix_html, "2.13.3", "850e292ff6e204257f5f9c4c54a8cb1f6fbc16ed53d360c2b780a3d0ba333867", [:mix], [{:plug, "~> 1.5", [hex: :plug, repo: "hexpm", optional: false]}], "hexpm"},
+  "phoenix_live_reload": {:hex, :phoenix_live_reload, "1.1.7", "425fff579085f7eacaf009e71940be07338c8d8b78d16e307c50c7d82a381497", [:mix], [{:file_system, "~> 0.2.1 or ~> 0.3", [hex: :file_system, repo: "hexpm", optional: false]}, {:phoenix, "~> 1.0 or ~> 1.2 or ~> 1.3 or ~> 1.4", [hex: :phoenix, repo: "hexpm", optional: false]}], "hexpm"},
+  "phoenix_pubsub": {:hex, :phoenix_pubsub, "1.1.2", "496c303bdf1b2e98a9d26e89af5bba3ab487ba3a3735f74bf1f4064d2a845a3e", [:mix], [], "hexpm"},
+  "plug": {:hex, :plug, "1.8.3", "12d5f9796dc72e8ac9614e94bda5e51c4c028d0d428e9297650d09e15a684478", [:mix], [{:mime, "~> 1.0", [hex: :mime, repo: "hexpm", optional: false]}, {:plug_crypto, "~> 1.0", [hex: :plug_crypto, repo: "hexpm", optional: false]}, {:telemetry, "~> 0.4", [hex: :telemetry, repo: "hexpm", optional: true]}], "hexpm"},
+  "plug_crypto": {:hex, :plug_crypto, "1.0.0", "18e49317d3fa343f24620ed22795ec29d4a5e602d52d1513ccea0b07d8ea7d4d", [:mix], [], "hexpm"},
   "poison": {:hex, :poison, "3.1.0", "d9eb636610e096f86f25d9a46f35a9facac35609a7591b3be3326e99a0484665", [:mix], [], "hexpm"},
-  "poolboy": {:hex, :poolboy, "1.5.1", "6b46163901cfd0a1b43d692657ed9d7e599853b3b21b95ae5ae0a777cf9b6ca8", [:rebar], [], "hexpm"},
-  "postgrex": {:hex, :postgrex, "0.13.3", "c277cfb2a9c5034d445a722494c13359e361d344ef6f25d604c2353185682bfc", [:mix], [{:connection, "~> 1.0", [hex: :connection, repo: "hexpm", optional: false]}, {:db_connection, "~> 1.1", [hex: :db_connection, repo: "hexpm", optional: false]}, {:decimal, "~> 1.0", [hex: :decimal, repo: "hexpm", optional: false]}], "hexpm"},
+  "poolboy": {:hex, :poolboy, "1.5.2", "392b007a1693a64540cead79830443abf5762f5d30cf50bc95cb2c1aaafa006b", [:rebar3], [], "hexpm"},
+  "postgrex": {:hex, :postgrex, "0.13.5", "3d931aba29363e1443da167a4b12f06dcd171103c424de15e5f3fc2ba3e6d9c5", [:mix], [{:connection, "~> 1.0", [hex: :connection, repo: "hexpm", optional: false]}, {:db_connection, "~> 1.1", [hex: :db_connection, repo: "hexpm", optional: false]}, {:decimal, "~> 1.0", [hex: :decimal, repo: "hexpm", optional: false]}], "hexpm"},
   "pre_commit": {:hex, :pre_commit, "0.1.4", "895991d91a6752ee475c37cb803aa61dd338102f59d5011cd7dbd1b84dd50796", [:mix], [], "hexpm"},
   "ranch": {:hex, :ranch, "1.3.2", "e4965a144dc9fbe70e5c077c65e73c57165416a901bd02ea899cfd95aa890986", [:rebar3], [], "hexpm"},
-  "ssl_verify_fun": {:hex, :ssl_verify_fun, "1.1.1", "28a4d65b7f59893bc2c7de786dec1e1555bd742d336043fe644ae956c3497fbe", [:make, :rebar], [], "hexpm"},
-  "unicode_util_compat": {:hex, :unicode_util_compat, "0.3.1", "a1f612a7b512638634a603c8f401892afbf99b8ce93a45041f8aaca99cadb85e", [:rebar3], [], "hexpm"}}
+  "ssl_verify_fun": {:hex, :ssl_verify_fun, "1.1.5", "6eaf7ad16cb568bb01753dbbd7a95ff8b91c7979482b95f38443fe2c8852a79b", [:make, :mix, :rebar3], [], "hexpm"},
+  "unicode_util_compat": {:hex, :unicode_util_compat, "0.4.1", "d869e4c68901dd9531385bb0c8c40444ebf624e60b6962d95952775cac5e90cd", [:rebar3], [], "hexpm"},
+}
diff --git a/test/library/books/books_test.exs b/test/library/books/books_test.exs
index a0e9175..c030bb5 100644
--- a/test/library/books/books_test.exs
+++ b/test/library/books/books_test.exs
@@ -392,8 +392,8 @@ defmodule Library.BooksTest do
   end
 
   describe "book_queue" do
-    alias Library.Books.BookQueue
     alias Library.Books.BookLoan
+    alias Library.Books.BookQueue
     alias Library.Users
 
     @valid_attrs %{book_id: 1, user_id: 1}
diff --git a/test/library_web/controllers/admin_controller_test.exs b/test/library_web/controllers/admin_controller_test.exs
index 4c3bc83..52a928a 100644
--- a/test/library_web/controllers/admin_controller_test.exs
+++ b/test/library_web/controllers/admin_controller_test.exs
@@ -2,8 +2,8 @@ defmodule LibraryWeb.AdminControllerTest do
   use LibraryWeb.ConnCase
   import Plug.Test
   alias Library.Books
-  alias Library.Users.User
   alias Library.Users
+  alias Library.Users.User
 
   @admin %{
     email: "hello@dwyl.com",