singleton-nats-0.4.2: CHANGELOG.md

# 0.4.2 [2018.09.18]
* Allow `singletons-2.5`.

# 0.4.1 [2018.05.02]
* Add a `Num Nat` instance.
* Implement `signum` in the `PNum`/`SNum` instances for `Nat`.
* Define defunctionalization symbols for `Lit`.
* Define `someNatVal`.

# 0.4.0.4 [2018.01.09]
* Allow `singletons-2.4`.

# 0.4.0.3 [2017.11.03]
* Allow `singletons-2.3`.