.travis.yml in capybara-screenshot-diff-0.4.0 vs .travis.yml in capybara-screenshot-diff-0.5.0

@@ -1,10 +1,11 @@
 language: ruby
 rvm:
-  - ruby-2.3.3
-  - jruby-9.1.6.0
-  - ruby-2.2.6
+  - ruby-2.4.1
+  - jruby-9.1.8.0
+  - ruby-2.3.4
+  - ruby-2.2.7
   - ruby-2.1.9
   - ruby-head
   - jruby-head
 
 gemfile:
@@ -17,11 +18,9 @@
 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