New rule: react-set-state-with-function

Enforce usage of the callback form of this.setState

// bad
this.setState({ ... });
// good
this.setState((prevState, props) => ...);

[vhfmag]

I don’t know much about tslint and tsutils API, so that may be not feasible, but I think the ideal would be that the rule allows objects if props and state aren’t used and enforce callback usage otherwise. Does that sound feasible?

[benbankes]

It seems like disallowing this.setState({...}); might be a little too restrictive. It seems like a better approach might be #172