Add a PyRosetta unit test for BindCraft (#753)
This doesn't test all of BindCraft, it just attempts to test the
PyRosetta portions of it, to make sure we don't have future regressions
on the use. (Like what was seen with PR #749)
One limitation is the lack of dalphaball. BindCraft uses it, but the I
do not think it's easy to use on the Rosetta test server. It's turned
off for this test, and hopefully not exercising the dalphaball-related
code doesn't cause too many issues.