👍 isIntersectionOf allows anything other than isObjectOf

[Milly]

Fixes #68

It's close to the functionality of the old AllOf.

Questions

Allow only one element?

const isMyObj = is.IntersectionOf([
  is.ObjectOf({a: is.String}),
]);

Currently...

• The type allows only one or more elements.
• The implementation also works with 0 elements.
  • In that case, the Predicate will always return true.

[lambdalisue]

LGTM. Thanks a lot 🎉