.travis.yml in capybara-screenshot-diff-0.3.0 vs .travis.yml in capybara-screenshot-diff-0.4.0

@@ -1,15 +1,32 @@
 language: ruby
 rvm:
+  - ruby-2.3.3
   - jruby-9.1.6.0
-  - 2.3.3
-  - 2.2.6
-  - 2.1.9
-  - jruby-head
+  - ruby-2.2.6
+  - ruby-2.1.9
   - ruby-head
-before_install: gem query -i -n ^bundler$ >/dev/null || gem install bundler
+  - jruby-head
 
+gemfile:
+  - gemfiles/rails50.gemfile
+  - gemfiles/rails42.gemfile
+
 env:
   - JRUBY_OPTS="--dev --debug"
 
 jdk:
   - oraclejdk8
+
+matrix:
+  exclude:
+    - rvm: ruby-head # Cannot build json 1.x
+      gemfile: gemfiles/rails42.gemfile
+    - rvm: ruby-2.1.9 # Not supported by Rails 5
+      gemfile: gemfiles/rails50.gemfile
+  allow_failures:
+    - rvm: jruby-head # FIXME: (uwe) Low coverage: https://github.com/jruby/jruby/issues/4404
+      gemfile: gemfiles/rails50.gemfile
+    - rvm: jruby-head # FIXME: (uwe) Low coverage: https://github.com/jruby/jruby/issues/4404
+      gemfile: gemfiles/rails42.gemfile
+
+before_install: gem query -i -n ^bundler$ >/dev/null || gem install bundler