Cap rake and json_pure versions on Ruby < 2.0

.travis.yml

@@ -4,16 +4,19 @@ language: ruby
 rvm:
   - 1.8.7
   - 1.9.3
-  - 2.0
-  - 2.1
-  - 2.2
+  - 2.0.0
+  - 2.1.10
+  - 2.2.5
+  - 2.3.1
 env:
   - PUPPET_GEM_VERSION="~> 3.7"
   - PUPPET_GEM_VERSION="~> 4.0"
 matrix:
   exclude:
     - rvm: 1.8.7
       env: PUPPET_GEM_VERSION="~> 4.0"
-    - rvm: 2.2
+    - rvm: 2.2.5
+      env: PUPPET_GEM_VERSION="~> 3.7"
+    - rvm: 2.3.1
       env: PUPPET_GEM_VERSION="~> 3.7"
   fast_finish: true

Gemfile

@@ -7,7 +7,17 @@ else
 end
 
 gem 'puppetlabs_spec_helper', :require => false
-# https://github.com/rspec/rspec-core/issues/1864
-gem 'rspec', '< 3.2.0', {"platforms"=>["ruby_18"]}
-gem 'rspec-puppet', '~> 2.1.0', :require => false
-gem 'metadata-json-lint',       :require => false
+gem 'metadata-json-lint',     :require => false
+
+## compatibility
+
+platforms :ruby_18 do
+  # https://github.com/rspec/rspec-core/issues/1864
+  gem 'rspec', '< 3.2.0',  :require => false
+  gem 'rake',  '< 11.0.0', :require => false
+end
+
+platforms :ruby_18, :ruby_19 do
+  gem 'json',      '< 2.0.0', :require => false
+  gem 'json_pure', '< 2.0.0', :require => false
+end