Changelog for single-tuple-0.1.2.0

Changelog for single-tuple

0.1.2.0

2021.05.21

Adding GHC.Tuple.Solo and GHC.Tuple.Unit as Single.

0.1.1.0

2020.05.26

Relaxing the upper bound for the base package.

0.1.0.0

2019.10.10

Release.