Add QUANTUM_DEPTH const
Add Color.{red,green,blue,alpha}_quantum props
Add Color.{red,green,blue,alpha}_int8 properties
Docstring and changelog of QUANTUM_DEPTH
Changelog of Color.{red,geen,blue}_{quantum,int8}
Fix broken build of ReadTheDocs
typo
Workaround to Travis CI
Merge remote-tracking branch 'upstream/master' into add-normalize
Adding test for single channel normalization (normalize_channel())