.travis.yml in act-fluent-logger-rails-0.3.1 vs .travis.yml in act-fluent-logger-rails-0.4.0

@@ -1,17 +1,23 @@
 language: ruby
 rvm:
   - 2.0.0-p648
   - 2.1.10
-  - 2.2.5
-  - 2.3.1
+  - 2.2.7
+  - 2.3.4
+  - 2.4.1
 gemfile:
   - gemfiles/rails_4.0.gemfile
   - gemfiles/rails_4.1.gemfile
   - gemfiles/rails_4.2.gemfile
   - gemfiles/rails_5.0.gemfile
+  - gemfiles/rails_5.1.gemfile
 matrix:
   exclude:
     - rvm: 2.0.0-p648
       gemfile: gemfiles/rails_5.0.gemfile
+    - rvm: 2.0.0-p648
+      gemfile: gemfiles/rails_5.1.gemfile
     - rvm: 2.1.10
       gemfile: gemfiles/rails_5.0.gemfile
+    - rvm: 2.1.10
+      gemfile: gemfiles/rails_5.1.gemfile