adding occurrences and refresh parameters to sensu_check type and sensu::check class
sensu-plugin: Allow one to install the gem

This PR aims to allow an administrator to decide to install
the sensu-plugin gem or not.
Make the rabbitmq_vhost defaults match the docs

Documentation and tests were updated, but the actual code wasn't. Make the
code match the documentation.
Merge pull request #211 from bodgit/rabbitmq_vhost

Make the rabbitmq_vhost defaults match the docs
Merge pull request #210 from Mylezeem/install_sensu_plugin

sensu-plugin: Allow one to install the gem
Merge pull request #200 from misterdorm/occurrencesandrefresh

adding occurrences and refresh parameters to sensu_check type and sensu:...