Add Subscription.to scope
Update constant access so we can reference the class under test less verbosely
Change from public to private
Fix gemspec
Remove active_record_spec_helper in favor of the one that comes with RSpectacular
Add Subscription.assign and allow it to create subscriptions
Fix database.yml to use SQLite
Update rspectacular to fix some bugs
Do not create a new Subscription when calling .assign if the subscription already exists
Subscription.assign raises an error if the subscriber or topic are invalid URIs
Intercept the  URIError in Subscription.assign and return a Hootenanny-specific error
Fix subscriber column on the subscriptions table
This is a Rails Engine so load Rails if loading the engine
Update spec wording
Add Hootenanny::Hub which can subscribe a callback to a topic
Potential subscribers can subscribe to new topics
Install strong_parameters
Potential subscribers receive error information if there is a problem