.travis.yml in percy-capybara-2.3.1 vs .travis.yml in percy-capybara-2.3.2

@@ -1,11 +1,13 @@
 language: ruby
 sudo: false
 cache: bundler
 rvm:
   - 1.9.3
-  - 2.1.1
-  - 2.2.2
+  - 2.2
   - ruby-head
+matrix:
+  allow_failures:
+  - rvm: ruby-head
 before_install:
   - gem update bundler
 script: xvfb-run bundle exec rspec