.travis.yml in kitchen-ec2-1.3.2 vs .travis.yml in kitchen-ec2-1.4.0

@@ -1,7 +1,11 @@
 language: ruby
 cache: bundler
 sudo: false
+branches:
+  only:
+  - master
 rvm:
-  - 2.2.6
-  - 2.3.1
+  - 2.2.8
+  - 2.3.5
+  - 2.4.2
   - ruby-head