Fix for #1942.  Added pickling test class for coordinates as well
updated Longitude and Quantity to properly use super().
Pickle the whole Quantity __dict__
added newline to end of file
Merge branch 'unit/pickling-quantities' of https://github.com/mdboom/astropy into mdboom-unit/pickling-quantities
removed unused unit
Merge pull request #1961 from ryanfox/wrap-angle-pickling

Fix for #1942.  Added pickling test class for coordinates as well