.travis.yml in isolator-0.4.0 vs .travis.yml in isolator-0.5.0

@@ -17,9 +17,11 @@
       gemfile: Gemfile
     - rvm: 2.4.3
       gemfile: Gemfile
     - rvm: 2.3.1
       gemfile: gemfiles/activerecord42.gemfile
+    - rvm: 2.2.2
+      gemfile: gemfiles/ruby_2.2.2.gemfile
   allow_failures:
     - rvm: ruby-head
       gemfile: gemfiles/railsmaster.gemfile
     - rvm: jruby-9.1.0.0
       gemfile: gemfiles/jruby.gemfile