.travis.yml in identity_cache-0.4.0 vs .travis.yml in identity_cache-0.4.1

@@ -1,18 +1,16 @@
 language: ruby
 
 rvm:
-  - 2.1
-  - 2.2.3
+  - '2.2.6'
+  - '2.3.3'
 
 gemfile:
   - Gemfile.rails42
   - Gemfile.rails50
 
 matrix:
   exclude:
-    - rvm: 2.1
-      gemfile: Gemfile.rails50
     - gemfile: Gemfile.rails50
       env: DB=postgresql
 
 env:
   - DB=mysql2