GerritForm.clean() attempts to set a gerrit_domain key based on the

gerrit_url that is provided, but otherwise doesn't perform any other

changes to the cleaned data. We had a unit test that checked that the

cleaned data (including domain) contained the values we expected, but

this posed problems on modern versions of Django, as the URLField used

for gerrit_url differed in its return value (the Django 1.6 version

includes a trailing slash while the 1.11 version does not).
Rather than attempting to normalize the version in the test, or key off

expected values by version, we're instead changing the purpose of the

test. It no longer checks the entirety of the cleaned data, but rather

is checking that gerrit_domain is properly set based off gerrit_url.

This avoids checking Django-specific results, sets a precedent in these

tests to have more specific unit tests for any custom keys added going

forward.

Unit tests pass on Django 1.6 and 1.11.