Adding Configuration#default_channels
Reworking Harbinger.deliver

Need to merge .call and .deliver into a singular method, so that
Harbinger can behave like an anonymous function.
Adding engine_cart
Updating specs to be Rspec 3 compliant
Updating README
Loosening gemspecs
Adding DatabaseChannel storage
Rearranging spec helpers

I want to bring the Hydramata::Works spec helpers over
Wiring up for engine cart behavior
Adding ability to store errors
Merge branch 'adding-database-tables'

* adding-database-tables:
  Adding ability to store errors
  Wiring up for engine cart behavior
  Rearranging spec helpers
  Adding DatabaseChannel storage