Update .travis.yml

Author: alvagante

.travis.yml

@@ -2,11 +2,13 @@ language: ruby
 rvm:
   - 1.8.7
   - 1.9.3
+script:
+  - "rake spec SPEC_OPTS='--format documentation'"
 env:
   - PUPPET_VERSION="~> 2.7.0"
   - PUPPET_VERSION="~> 3.0.0"
   - PUPPET_VERSION="~> 3.1.0"
-  - PUPPET_VERSION="~> 3.2.0"
+  - PUPPET_VERSION="~> 3.6.0"
 matrix:
   exclude:
     - rvm: 1.9.3