.travis.yml in slack-ruby-client-0.7.7 vs .travis.yml in slack-ruby-client-0.7.8

@@ -2,15 +2,15 @@
 
 cache: bundler
 
 matrix:
   include:
-    - rvm: 2.3.0
+    - rvm: 2.3.1
       script:
         - bundle exec danger
-    - rvm: 2.3.0
+    - rvm: 2.3.1
       env: CONCURRENCY=celluloid-io
-    - rvm: 2.3.0
+    - rvm: 2.3.1
       env: CONCURRENCY=faye-websocket
     - rvm: 2.2
     - rvm: 2.1
     - rvm: 2.0
     - rvm: rbx-2