have travis use env var

.travis.yml

@@ -1,15 +1,15 @@
 language: rust
 sudo: required
 os:
-- linux
-- osx
+  - linux
+  - osx
 rust:
-- stable
+  - stable
 services:
-- docker
+  - docker
 before_script:
-- rustup component add rustfmt
-- rustup component add clippy
+  - rustup component add rustfmt
+  - rustup component add clippy
 script:
   # Require `cargo fmt` to have been run.
   - cargo fmt -- --check
@@ -25,8 +25,7 @@ before_deploy:
   - ./build-release geocode-csv "${TRAVIS_TAG}-${TRAVIS_OS_NAME}"
 deploy:
   - provider: releases
-    api_key:
-      secure: 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
+    api_key: $GITHUB_TOKEN
     file_glob: true
     file: "geocode-csv-${TRAVIS_TAG}-${TRAVIS_OS_NAME}.*"
     skip_cleanup: true