make spec test for rabbitmq::repo::rhel run

The file spec/classes/rabbitmq_repo_rhel.rb was missing _spec in its
filename to let the spec tests for rabbitmq::repo::rhel run.
extra apt pinning stuff is not necessary
fetch rabbitmq public signing key from rabbitmq.com
add spec tests for rabbitmq::repo::apt
remove superfluous file spec/fixtures/manifests/site.pp
Replaced :admin in rabbitmq_user type with :tags and fixes for RabbitMQ 2.6.0+

http://lists.rabbitmq.com/pipermail/rabbitmq-discuss/attachments/20110831/36015373/attachment.txt
Fixing tests for :admin to :tags user change.
Fixing more tests.
Removing some inadvertantly left in munge test code from user type.
Cleaned up missing desc in plugin, user_permissions, and vhost
Fixed user test still referencing admin parameter
Fixing clustering config
Allow different cluster node types (such as ram nodes)
fixing typo in config
Add clustering changes to tests
merging 2.6.0
merged changes
added Gemfile