rapid_triangulation command line program

This merge requests adds rapidpe_triangulation as a command line program. It modifies the setup.py file to add a dependency to bilby.

For more details please see: https://git.ligo.org/groups/rapidpe-rift/-/wikis/Search-pipeline-based-triangulation

As suggested by Patrick Brady, we want something that works in place in order to begin testing. We will eventually optimize the required time delay funcions through vectorization if necessary.