Test puppet 4.latest against the latest ruby packaged with puppet-agent

.travis.yml

@@ -24,9 +24,9 @@ matrix:
     script: bundle exec rake beaker
     services: docker
     sudo: required
-  - rvm: 2.1.6
+  - rvm: 2.1.9
     bundler_args: --without system_tests
-    env: PUPPET_GEM_VERSION="~> 4.5" STRICT_VARIABLES="yes"
+    env: PUPPET_GEM_VERSION="~> 4.7" STRICT_VARIABLES="yes"
   - rvm: 2.1.6
     bundler_args: --without system_tests
     env: PUPPET_GEM_VERSION="~> 3.5" FUTURE_PARSER="yes"