Recipe and batch categories are now set by default.  Fixes #32.

Categories are now set whenever recipes or batches are saved.  A new
test was added to confirm that the new feature worked.
Appellations and natural work now.  Fixes #39.

The tests are getting a little weighty, and I can probably skip using
selenium for any test that doesn't check the body of the output for a
failure or success message.  Look into creating an object from
self.client maybe?
Merge branch 'hotfix/1.3.1' into develop