Add zanata-python-client to TEST_DEPENDENCIES
Add zanata-python-client to TEST_DEPENDENCIES

The tests run the translation-canary test which needs the translations,
so this makes sure you can pull them down for the test.

jkonecny12/blivet,vojtechtrefny/blivet,jkonecny12/blivet,AdamWill/blivet,rvykydal/blivet,vpodzime/blivet,vojtechtrefny/blivet,rvykydal/blivet,vpodzime/blivet,AdamWill/blivet