Re-enable `react/no-deprecated` rule after its been adjusted

[Timer]

Right now react/no-deprecated warns multiple times over on deprecated lifecycle methods.

This behavior isn't very optimal -- we should file an issue with ESLint and ask them to remove it once a formal warning is added to React.

[gaearon]

To be more precise, I don't think eslint-plugin-react would remove it (and the rule itself is useful) but I'd prefer to activate after React itself starts considering them deprecated (and the users have run the codemod).

[Timer]

Sure, that makes sense.

[abhinavsingi]

@gaearon @Timer Should this be enabled now?