Get coordinates with epochs

[kelle]

Most sources do not have epochs which make it difficult to properly predict locations using proper motions. We need to systematically get good coords and epochs for all sources.

Maybe start with SIMBAD.

[kelle]

After discussion with @rothermichaustin , we decided this should be the likely order of operations in order to get epochs:

1. Gaia
2. CatWISE
3. PanSTARRS
4. 2MASS.