v2.1.0

DitherPunk v2.1.0

Diff since v2.0.1

Closed issues:

• store the color result using IndirectArrays (#28)
• Make invert_map part of OrderedDither struct instead of binarydither! kwarg (#48)

Merged pull requests:

• Use IndirectArrays (#47) (@adrhill)
• Make invert_map keyword argument of OrderedDither (#50) (@adrhill)
• Precompute inverted ordered dithering matrix (#51) (@adrhill)
• Increase code coverage (#52) (@adrhill)