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.
state = {
          text: 'hello',
        };
        renderConsumer = context => {
          Scheduler.unstable_yieldValue('App#renderConsumer');
          return <span prop={this.state.text} />;
        };
        render() {
          Scheduler.unstable_yieldValue('App');
          return (
            <Context.Provider value={this.props.value}>
              <Consumer>{this.renderConsumer}</Consumer>
            </Context.Provider>
          );
        }
      }
      
      let inst;
      ReactNoop.render(<App value={1} ref={ref => (inst = ref)} />);
      expect(Scheduler).toFlushAndYield(['App', 'App#renderConsumer']);
      expect(ReactNoop.getChildren()).toEqual([span('hello')]);
      
      inst.setState({text: 'goodbye'});
      expect(Scheduler).toFlushAndYield(['App', 'App#renderConsumer']);
      expect(ReactNoop.getChildren()).toEqual([span('goodbye')]);
    });
    it('warns when reading context inside render phase class setState updater', () => {
      const ThemeContext = React.createContext('light');
      class Cls extends React.Component {