.travis.yml in trix-rails-2.2.0 vs .travis.yml in trix-rails-2.3.0

@@ -1,17 +1,21 @@
 language: ruby
 rvm:
-  - 2.3.4
-  - 2.4.1
-  - 2.5.1
+  - 2.3.8
+  - 2.4.7
+  - 2.5.6
+  - 2.6.4
 gemfile:
-  - gemfiles/rails_4.2.gemfile
   - gemfiles/rails_5.0.gemfile
   - gemfiles/rails_5.1.gemfile
   - gemfiles/rails_5.2.gemfile
   - gemfiles/rails_5.2.1.gemfile
   - gemfiles/rails_6.0.0.gemfile
   - gemfiles/rails_master.gemfile
 matrix:
   allow_failures:
     - gemfile: 'gemfiles/rails_master.gemfile'
-before_install: gem install bundler -v 1.11.2
+    - gemfile: gemfiles/rails_6.0.0.gemfile
+      rvm: 2.3.8
+    - gemfile: gemfiles/rails_6.0.0.gemfile
+      rvm: 2.4.7
+before_install: gem install bundler -v '~> 2.0'