.travis.yml in mixlib-install-0.5.0 vs .travis.yml in mixlib-install-0.6.0

@@ -1,4 +1,7 @@
 language: ruby
 sudo: false
 rvm:
-  - 2.2.1
+  - 2.2
+  - 2.1
+  - 1.9.3
+  - ruby-head