.travis.yml in mixlib-versioning-1.2.1 vs .travis.yml in mixlib-versioning-1.2.2

@@ -2,14 +2,17 @@
 language: ruby
 cache: bundler
 
 matrix:
   include:
-    - rvm: 2.3.4
+    - rvm: 2.0
+    - rvm: 2.2
+    - rvm: 2.3
     - rvm: 2.4.1
     - rvm: ruby-head
   allow_failures:
     - rvm: ruby-head
+
 branches:
   only:
   - master
 
 bundler_args: --without changelog