Fixup test deps

These were revealed broken by running in non-fast mode.

Testing Done:
$ rm -rf pants.pex dist/ && ./pants build tests/python/pants_test:all

CI is went green here: https://travis-ci.org/pantsbuild/pants/builds/34972075

Bugs closed: 369, 569

Reviewed at https://rbcommons.com/s/twitter/r/1016/