Allow time format and scale strings to be case-insensitive
Refactor astropy.coordinates to use six instead of 2to3
Allow scaled dimensionless units for CDS format
Merge pull request #1128 from embray/format-case

Allow time format and scale strings to be case-insensitive
Touch-ups: --- is dimensionless; unicode MULTIPLICATION SIGN can be used
Merge pull request #1460 from mdboom/coordinates/six

Refactor astropy.coordinates to use six instead of 2to3
Merge pull request #1465 from mhvk/units-cds-scaled-dimensionless

Allow scaled dimensionless units for CDS format