updates for O3 replay

Mostly addresses #237

Major changes:

• In addition to the json file from GraceDB, we also pull down PSDs from the coinc.xml
• Use the SNRs for each detector to determine the time reference and reference frame
• Disable pesummary job
• Lower the maximum frequency to fit PSD from GraceDB - this may still be problematic
• Add first pass at setting the chirp mass prior range for lower-mass systems
• Update default sampler kwargs
• New --settings argument, this should be a json file containing keys for the configuration file. The intention of this is to easily enable downstream tasks to change the sampler/settings. This will avoid having to do a new release of bilby_pipe in order to tune online settings. Here's an example file to switch to PyMultiNest

{
    "sampler": "pymultinest",
    "sampler_kwargs": {"nlive": 100, "n_clustering_params": 13, "dlogz": 1, "temporary_directory": false}
}

To do:

• Add the executable from !400 (merged) to the pipeline
• Decide if we want to use the PSDs from the coinc, figure out stability

cc @soichiro.morisaki @gregory.ashton