Fix typo in doctest
Raise a NotImplementedError when fitting composite models.
clarify error message
add changelog entry
use correct PR number
Fix typo in doc string

uncertaintys -> uncertainties
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
Whitespace
fix for warning that says "automodapi" when it should be "automodsumm"
Added "automodapi_writereprocessed" option to automodapi
Expanded spectral() equivalencies to include angular wave number.
Added note to change log.
Use six for astropy.cosmology
Merge pull request #1890 from mdboom/cosmology/six

Use six for astropy.cosmology
Merge pull request #1899 from pllim/wavenum-energy

Expanded spectral() equivalencies to include angular wave number.
Merge pull request #1923 from joergdietrich/patch-1

Fix typo in doc string