Trying to fix .travis.yml for RMG-database project.

Trying to get the travis config for RMG-database to build RMG-Py (just as a dependency) then test the RMG-database for consistency.

Wait until this PR is building properly (or at least running the tests - even if they don't pass, with those new families) before merging. It's a GreenGroup branch, so you can add commits to fix it