.travis.yml in pwwka-0.14.0 vs .travis.yml in pwwka-0.15.0

@@ -1,9 +1,9 @@
 language: ruby
 sudo: true
 rvm:
-  - 2.3.1
-  - 2.2.4
+  - 2.3.3
+  - 2.4.2
 services:
   - docker
 before_install:
   - docker-compose up -d
 script: