This patch does several things at once:
- Remove mox from KarborApiTest. Use mock instead
of mox3 to mock out the karborclient.
- Use mock to mout the karborclient.
- Drop mox3 from the test-requirements.txt.
This is apart of the mox community goal for Rocky.
Change-Id: Iea9e65778777746682895521f17ca69f5c27f7fd
Signed-off-by: Charles Short <zulcss@gmail.com>