Corrections to gemfiles/travis config

* The rails-5.1 gemfiles were building against edge rails, not 5.1.
* Added rails-5.2 gemfiles
* Remove builds for Gemfile (edge rails) for rubies older than 2.4.1

Author: lostapathy

.travis.yml

@@ -22,6 +22,8 @@ gemfile:
   - gemfiles/Gemfile.rails-5.0.x.sprockets-4.x
   - gemfiles/Gemfile.rails-5.1.x
   - gemfiles/Gemfile.rails-5.1.x.sprockets-4.x
+  - gemfiles/Gemfile.rails-5.2.x
+  - gemfiles/Gemfile.rails-5.2.x.sprockets-4.x
 
 matrix:
   exclude:
@@ -39,6 +41,10 @@ matrix:
       rvm: 2.0.0
     - gemfile: Gemfile
       rvm: 2.1
+    - gemfile: Gemfile
+      rvm: 2.2.7
+    - gemfile: Gemfile
+      rvm: 2.3.4
     - gemfile: gemfiles/Gemfile.rails-5.0.x
       rvm: 1.9.3
     - gemfile: gemfiles/Gemfile.rails-5.0.x
@@ -63,6 +69,18 @@ matrix:
       rvm: 2.0.0
     - gemfile: gemfiles/Gemfile.rails-5.1.x.sprockets-4.x
       rvm: 2.1
+    - gemfile: gemfiles/Gemfile.rails-5.2.x
+      rvm: 1.9.3
+    - gemfile: gemfiles/Gemfile.rails-5.2.x
+      rvm: 2.0.0
+    - gemfile: gemfiles/Gemfile.rails-5.2.x
+      rvm: 2.1
+    - gemfile: gemfiles/Gemfile.rails-5.2.x.sprockets-4.x
+      rvm: 1.9.3
+    - gemfile: gemfiles/Gemfile.rails-5.2.x.sprockets-4.x
+      rvm: 2.0.0
+    - gemfile: gemfiles/Gemfile.rails-5.2.x.sprockets-4.x
+      rvm: 2.1
 
 notifications:
   email: false

gemfiles/Gemfile.rails-5.1.x

@@ -1,7 +1,6 @@
 source 'https://rubygems.org'
 gemspec path: '..'
 
-gem 'actionpack', github: 'rails/rails', branch: 'master'
-gem 'railties', github: 'rails/rails', branch: 'master'
-gem 'rack', github: 'rack/rack', branch: 'master'
+gem 'actionpack', '~> 5.1.0'
+gem 'railties', '~> 5.1.0'
 gem 'sprockets', github: 'rails/sprockets', branch: '3.x'

gemfiles/Gemfile.rails-5.2.x

@@ -0,0 +1,6 @@
+source 'https://rubygems.org'
+gemspec path: '..'
+
+gem 'actionpack', '~> 5.2.0'
+gem 'railties', '~> 5.2.0'
+gem 'sprockets', github: 'rails/sprockets', branch: '3.x'

gemfiles/Gemfile.rails-5.2.x.sprockets-4.x

@@ -0,0 +1,6 @@
+source 'https://rubygems.org'
+gemspec path: '..'
+
+gem 'actionpack', '~> 5.2.0'
+gem 'railties', '~> 5.2.0'
+gem 'sprockets', github: 'rails/sprockets', branch: 'master'