Fix typo in doctest
Raise a NotImplementedError when fitting composite models.
clarify error message
add changelog entry
use correct PR number
Add test for array coordinate length (issue #1761)
Add len() to coordinates

Closes #1761
Add tests of len() for scalar coordinate and length 1 coordinate
Add changelog entry for 1761
Correct the change log message
changed .hms and .dms attributes to output a named tuple instead of a regular tuple
fixed tests to match new dms/hms
fix docstrings to reflect namedtuple dms/hms
added absdms attribute to Angle
Accept empty string/None/False as `sep` for Angle.to_string
Add test for empty string `sep` of Angle
Added `format` examples to coordinates docs
update changelog
Update changelog
Fix problem with names arg colliding with existing names