.travis.yml in env_pull_request-0.3.3 vs .travis.yml in env_pull_request-1.0.0

@@ -3,11 +3,12 @@
 #          And this will show ENV accidentally in CI log.
 language: "ruby"
 rvm:
   - "1.9"
   - "2.0"
-  - "2.1"
-  - "2.2"
+  - "2.1.10"
+  - "2.2.5"
+  - "2.3.1"
   - "ruby-head"
 matrix:
   allow_failures:
     - rvm: "ruby-head"
 before_install: