Use getApolloState instead relying on reduxRootKey

[sheerun]

I hope I got it well. It may or may not require major bump.

I'd be really glad if you released it asap, as I use my own redux store.

[apollo-cla]

@sheerun: Thank you for submitting a pull request! Before we can merge it, you'll need to sign the Meteor Contributor Agreement here: https://contribute.meteor.com/

[sheerun]

This is simpler and more accurate implementation of #223, should resolve #221

[sheerun]

Actually it shoudn't require major bump as queryManager.getApolloState() was available in previous versions.

[stubailo]

I'm a little uncomfortable because this isn't strictly a "public API" but it definitely works for now! We'll just need to be careful to not remove that function, or rename queryManager.

[sheerun]

CI fails for non-related reasons.. I guess if you figure out public API for getting apollo state, you can change it. At least it's less hacky than manually fetching it by reduxRootSelector (that can be both string or function)... and backward compatible.

[stubailo]

Yeah I think this is a great solution right now, let's do it!

[sheerun]

@stubailo Any chance to release it soon? :)

[jbaxleyiii]

@sheerun I'll get this out today!