Move the panel mocks to a separate method on TestCase

We need to remove the panel mocks in Tuskar-UI tests, because they
import and register the admin panel as their side effect. To do that
easily, I'm moving that part into a separate method.

Partial-bug: #1384683
Change-Id: Ica366c0b9f680049a74e94007a563ffdb492e4f4
Imported Translations from Transifex

For more information about this automatic import see:
https://wiki.openstack.org/wiki/Translations/Infrastructure

Change-Id: I1452be108c68ffef7fd85f60eeaad5ec0f9c0f5b
Merge "Move the panel mocks to a separate method on TestCase"
Merge "Imported Translations from Transifex"