Minimum hets version updated.

Should avoid hets to fail with "unrecognized option `-C'".
Translated HetsTest into RSpec.

Now the failing tests produce helpful error messages.
OntologyTest fixed
OntologyVersionTest fixed
AutocompleteTest fixed
CategoryTest set to pending
Merge branch 'develop' into staging to fix remaining tests (#387)

Conflicts:
	app/models/ontology.rb