Numeric refined types for Byte, Short, BigInt and BigDecimal.

[Michaelt293]

Added numeric refined types for Byte, Short, BigInt and BigDecimal.

[fthomas]

Thanks for the PR, @Michaelt293! To make this change binary compatible forwarders of all new types must be added to NumericTypesBinCompat1 and it cannot be mixed into NumericTypes. In types/all.scala you then need a new trait:

trait AllTypesBinCompat1 extends NumericTypesBinCompat1

which is then mixed into the allobject. We have a similar situation here: https://github.com/fthomas/refined/blob/master/modules/core/shared/src/main/scala/eu/timepit/refined/predicates/all.scala

[Michaelt293]

Thanks for your help @fthomas. Was very helpful :)

[fthomas]

LGTM. Thanks again, @Michaelt293!