Migrate from glue.ligolw to ligo.lw
Glue is no longer supported, and both RIFT and the rapidPE/RIFT pipeline have switched to ligo.lw to provide what rapidPE currently gets from glue.ligolw. This is causing a file formatting issue when mixing parts of rapidPE and RIFT (see rapidpe-rift-submission-scripts#20).
We need to migrate everything in rapidPE to use the new package. Hopefully this is just a matter of changing what we import, but there might be changes to the API as well which will require more involved changes. For reference, here are the API docs for both packages