.travis.yml in attestor-2.2.0 vs .travis.yml in attestor-2.2.1

@@ -1,9 +1,20 @@
 ---
 language: ruby
+sudo: false
+cache: bundler
 bundler_args: --without metrics
 script: rake test:coverage:run
 rvm:
+  - '1.9.3'
   - '2.0'
+  - '2.1'
+  - '2.2'
   - ruby-head
+  - rbx-2 --1.9
   - rbx-2 --2.0
   - jruby-9.0.0.0.pre1
+  - jruby-head
+matrix:
+  allow_failures:
+    - rvm: ruby-head
+    - rvm: jruby-head