Ingest resolved children and close companions

[lesliech1004]

Helper method in sources.py that ingests close companions and resolved children regardless of how close they are to each other. It first checks if the source preexists in the database, then ingests the source.

Closes issue #175

[kelle]

instead of a dedicated function, I think this would be better as a flag in ingest_source. Something like, ignore_neighbors = True/False. Default would be False but when ingesting close companions, it would be set to True.

[kelle]

This looks like a good start!

• when duplicates are found, please add a logger.warning with the potential duplicates found.
• what happens when ingest_neighbors = True but ra/dec is not provided?
• add tests in test_source.py.
  • ingesting a close companion with ingest_neighbors = False and it shouldn't work.
  • ingest a close companion with ingest_neighbors = True and it should work.