Change log

0.3

• Add freer rigid selective functors: Control.Selective.Rigid.Freer.
• Rename Control.Selective.Free.Rigid to Control.Selective.Rigid.Free.
• Add free selective functors: Control.Selective.Free.
• Switch to more conventional field names in SelectA and SelectM.

0.2

• Make compatible with GHC >= 8.0.2.
• Add another free construction Control.Selective.Free.
• Add several new Selective instances.