.travis.yml in danger-textlint-1.2.1 vs .travis.yml in danger-textlint-1.2.2

@@ -2,13 +2,11 @@
 cache:
   directories:
     - bundle
 
 rvm:
-  - 2.1
-  - 2.2
-  - 2.3
   - 2.4
   - 2.5
+  - 2.6
 
 script:
     - bundle exec rake spec