Just about every time I set up a new `Context.Provider`, I end up accidentally specifying a `values` prop rather than `value`.  While it's a minor error, generally I build the container in which the provider resides and commit it to the code base before I ever use it.  It's only later when I go to use it that I realize I did it again.  Since the `Context.Provider` seems pretty much useless without a `value` prop specified, I'd love it if there was a prop error if it is missing... especially if another prop is defined on the `Context.Provider` instead.
render() {
        return (
          <div className="purple">
            <Child />
          </div>
        );
      }
    }
    const Child = () => {
      return <moo />;
    };
    const renderer = ReactTestRenderer.create(<Component />);
    expect(renderer.toJSON()).toEqual({
      type: 'div',
      props: {className: 'purple'},
      children: [{type: 'moo', props: {}, children: null}],
    });
  });
  it('renders some basics with an update', () => {
    let renders = 0;
    class Component extends React.Component {