`any` proptype should not be marked as required

In the following example, foo probably should not be marked as required:

type Props = {
  foo: any,
}

const MyComp = (props: Props) => <div />

<MyComp foo={null} />
// Failed prop type: The prop `foo` is marked as required in `MyComp`, but its value is `null`.

[marcind]

@echenley did not run the updated code but looking at the test case coverage, this seems like it should work as I would expected

type Props {
   foo?: any
}
const Comp = (props: Props) => null;

to result in

const Comp = (props) => null;
Comp.propTypes = {
   foo: require('prop-types').any,
}

i.e. the behavior before the first PR

So :shipit:

[brigand]

For completeness of this thread, this is the new test echenley added. It handles both cases properly.

type Props = {
  requiredAny: any,
  optionalAny?: any,
};
const Foo = (props: Props) => <div />

Foo.propTypes = {
  requiredAny: function requiredAny(props, propName, componentName) {
    if (!Object.prototype.hasOwnProperty.call(props, propName)) {
      throw new Error('Prop \`' + propName + '\` has type \\\\'any\\\\' or \\\\'mixed\\\\', but was not provided to \`' + componentName + '\`. Pass undefined or any other value.');
    }
  },
  optionalAny: require('prop-types').any
};