Remove unused test function

The appconfig function in keystone.tests.TestCase wasn't used.
This change removes it.

Change-Id: I5377b7a3a42df1d111736f9cce0e2f74fa5931e2
Remove netifaces requirement

netifaces is not required to run the tests, so remove it from
the requirements.

Related-Bug: #1266513
Change-Id: Ifb3b262f47d629670b06c670353dbe798af4dc03
Merge "Remove unused test function"
Merge "Remove netifaces requirement"