Add Ruby 2.5 and Rails 5.1 to the testing matrix on Travis

.travis.yml

@@ -4,38 +4,47 @@ sudo: false
 rvm:
   - 2.0.0
   - 2.1.10
-  - 2.2.6
-  - 2.3.3
-  - 2.4.1
+  - 2.2.9
+  - 2.3.6
+  - 2.4.3
+  - 2.5.0
 gemfile:
   - gemfiles/rails_3.gemfile
   - gemfiles/rails_4.gemfile
   - gemfiles/rails_4.1.gemfile
   - gemfiles/rails_4.2.gemfile
   - gemfiles/rails_5.gemfile
+  - gemfiles/rails_5.1.gemfile
   - gemfiles/sinatra.gemfile
 matrix:
   exclude:
+    # Rails 3 requires Ruby 1.8.7 or newer
+    # Rails 4 prefers Ruby 2.0 and requires 1.9.3 or newer
+    # Rails 4.1 recommends Ruby 2.1 and requires 1.9.3 or newer
+    # Rails 4.2.1 recommends Ruby 2.2 and requires 1.9.3 or newer
+    # Rails 5 requires Ruby 2.2.2 or newer
+    # Sinatra 2 requires Ruby 2.2.2 or newer
     - rvm: 2.0.0
       gemfile: gemfiles/rails_5.gemfile
+    - rvm: 2.0.0
+      gemfile: gemfiles/rails_5.1.gemfile
     - rvm: 2.0.0
       gemfile: gemfiles/sinatra.gemfile
     - rvm: 2.1.10
       gemfile: gemfiles/rails_5.gemfile
+    - rvm: 2.1.10
+      gemfile: gemfiles/rails_5.1.gemfile
     - rvm: 2.1.10
       gemfile: gemfiles/sinatra.gemfile
-    - rvm: 2.2.6
-      gemfile: gemfiles/rails_3.gemfile
-    - rvm: 2.3.3
-      gemfile: gemfiles/rails_3.gemfile
-    - rvm: 2.4.1
-      gemfile: gemfiles/rails_3.gemfile
-    - rvm: 2.4.1
+    # Rails 4 and 4.1 fails with Ruby newer then 2.3
+    - rvm: 2.4.3
+      gemfile: gemfiles/rails_4.gemfile
+    - rvm: 2.4.3
+      gemfile: gemfiles/rails_4.1.gemfile
+    - rvm: 2.5.0
       gemfile: gemfiles/rails_4.gemfile
-    - rvm: 2.4.1
+    - rvm: 2.5.0
       gemfile: gemfiles/rails_4.1.gemfile
-    - rvm: 2.4.1
-      gemfile: gemfiles/rails_4.2.gemfile
 before_install:
   - gem install bundler
 script:

config.gemspec

@@ -49,7 +49,7 @@ Gem::Specification.new do |s|
   end
 
   if ENV['TRAVIS']
-    s.add_development_dependency 'simplecov', '~> 0.15.1'
+    s.add_development_dependency 'simplecov', '~> 0.13.0'
     s.add_development_dependency 'codeclimate-test-reporter', '~> 1.0.8'
   end
 end