Renaming spec page objects for clarity

Also adding a new spec regarding citation creation.
Adding explicit require for underlying constants

I'm wondering if I'm at odds with Rails autoload and eager_load. But
for now this works.
Adding documentation artifacts

[skip ci]
Merge pull request #26 from ndlib/adding-artifacts

Adding documentation artifacts
Removing the "leaky abstraction"

Instead focusing on target policies instead of generalized
Adding Sipity::Conversions::ConvertToPermanentUri

Exposing a more "permanent" solution to the URI generation. Its not
a final URI format but the exposed conversion service is a good start.