.travis.yml in smtpapi-0.0.12 vs .travis.yml in smtpapi-0.1.0

@@ -1,13 +1,10 @@
 language: ruby
 rvm:
   - "1.9.3"
   - "2.0.0"
-  - "2.1.0"
-  - "2.1.2"
-  - "2.1.3"
-  - "2.1.4"
   - "2.1.5"
+  - "2.2.1"
 before_script:
   - bundle install
 script:
   - rubocop --fail-level=W
   - rake test