Add formula for git-review

git-review is a git plugin for handling gerrit-based codereviews. It's an application written in Python, and I tried to follow all the newish conventions on how to write such formulas.
git-review contains also a full testsuite, but the problem is that it requires additional dependencies that would have to be installed (possibly in a temporary virtualenv?). What is the policy in this case? Should the original testsuite be used if possible, or a simply "installation testsuite" is enough?