Provide a collection of Predicate functions

[evilsoft]

Maximum exposure

This PR addresses issue#21 and exposes all the internal predicate functions to the outside world. The following have be added to the public API and moved from the internal folder and into a new predicates folder:

• isApplicative
• isApply
• isArray
• isEmpty
• isFunction
• isFunctor
• isMonoid
• isNil
• isNumber
• isObject
• isSemigroup
• isString

In addition to these existing functions, some new ones have been added, just to flesh them out a bit more:

• isBoolean
• isInteger
• isMonad
• isSetoid
• isTraversable

Also as a 🍠 Bonus I add a not function that takes a predicate function and returns a new predicate function that will negate the result of the passed function.

const { not, isNil, safe } = crocks

const f =
  safe(not(isNil))

f(undefined) // Maybe.Nothing
f(23) // Maybe.Just 23

[evilsoft]