.travis.yml in slack-ruby-bot-0.15.0 vs .travis.yml in slack-ruby-bot-0.16.0

@@ -5,25 +5,21 @@
 matrix:
   include:
     - rvm: 2.6.5
       script:
         - bundle exec danger
-    - rvm: 2.3.0
+    - rvm: 2.4.0
       env: CONCURRENCY=celluloid-io
-    - rvm: 2.3.0
+    - rvm: 2.4.0
       env: CONCURRENCY=faye-websocket
-    - rvm: 2.3.0
+    - rvm: 2.4.0
       env: CONCURRENCY=async-websocket
     - rvm: 2.6.5
-      env: CONCURRENCY=celluloid-io WITH_GIPHY=true
+      env: CONCURRENCY=celluloid-io
     - rvm: 2.6.5
-      env: CONCURRENCY=faye-websocket WITH_GIPHY=true
+      env: CONCURRENCY=faye-websocket
     - rvm: 2.6.5
-      env: CONCURRENCY=celluloid-io WITH_GIPHY_CLIENT=true
-    - rvm: 2.6.5
-      env: CONCURRENCY=faye-websocket WITH_GIPHY_CLIENT=true
-    - rvm: 2.6.5
-      env: CONCURRENCY=async-websocket WITH_GIPHY_CLIENT=true
+      env: CONCURRENCY=async-websocket
     - rvm: ruby-head
     - rvm: jruby-head
   allow_failures:
     - rvm: ruby-head
     - rvm: jruby-head