.travis.yml in slack-ruby-client-0.4.0 vs .travis.yml in slack-ruby-client-0.5.0

- old
+ new

@@ -13,5 +13,8 @@
     - rvm: jruby-head
 
 git:
   submodules: false
 
+env:
+  - CONCURRENCY=celluloid-io
+  - CONCURRENCY=faye-websocket