.travis.yml in knife-google-3.1.1 vs .travis.yml in knife-google-3.2.0

@@ -1,10 +1,18 @@
 language: ruby
 cache: bundler
+dist: trusty
 sudo: false
 rvm:
-- 2.2.5
-- 2.3.1
+  - 2.2.7
+  - 2.3.4
+  - 2.4.1
+  - ruby-head
+  
+matrix:
+  allow_failures:
+    - rvm: ruby-head
+
 branches:
   only:
   - master
 notifications:
   slack: