Update to latest version of react-reconciler

[wearhere]

Even though the README says that this library will work with React's latest v16.x.x, it does not seem that we can use the new lifecycles and context APIs introduced in React v16.3. For example:

• if I implement the new lifecycle APIs on components, they're not called
• if I try to mount a component <Consumer>{value => /* renderable */}</Consumer> in the tree, I get an error Invariant Violation: Element type is invalid: expected a string (for built-in components) or a class/function (for composite components) but got: object.
• I get an error trying to use React.createRef

I think this is because this library is using an outdated version of react-reconciler. That's where the latter invariant violation originates, and if I look up that invariant in the latest version of react-reconciler, there is logic about the new context API that does not exist in the version used by this library.

[Yomguithereal]

You are right. Unfortunately I don’t have much time right now. I will of course review and probably accept a PR fixing this issue :)