Update ``Resource`` model definition.

https://github.com/madewithbytes/us_ignite/issues/173

The model tests have been updated to reflect the new
``Resources`` structure.
Update admin section for the ``Resources``.
Update dummy ``Resource`` generator.

https://github.com/madewithbytes/us_ignite/issues/173

Updated the mechanics to generate ``Resources``.
Amend mechanics on the site related to ``Resources``

https://github.com/madewithbytes/us_ignite/issues/173

This is a heavy changeset that makes sure that the
updates of the resources work with the rest of the site.

The changes have been driven by the existing ``unittests``.
Update ``Resource`` add form.
Add ``AutoSlug`` for the ``ResourceType`` and ``Sector`` models.

https://github.com/madewithbytes/us_ignite/issues/173

The slugs will come in-handy if a filtering view is required,
the tests have been updated to reflect this changes.
Add management command to add initial ``Resources`` fixtures.

https://github.com/madewithbytes/us_ignite/issues/173
Make sure the resources fixtures are loaded with the dummy content.
Load initial fixtures with fabric.

https://github.com/madewithbytes/us_ignite/issues/173