Move auth logic out into redux

[mikeyhogarth]

There is loads we could do to make this better but this is an initial pass at moving your auth logic out of your views and into a more manageable state model.

Addresses #26

[mikeyhogarth]

The setup in this implementation is really verbose - actions, action-creators and reducers all in separate files, reducers pre-set up using combineReducers to allow them to grow accross different files in the future...

... when you're used to this, I'll show you how we can cut down the code massively using a couple of patterns but I didn't want to just go straight in at that level initially (you won't feel the benefit otherwise 😈 )

[mikeyhogarth]

Also just in case you're feeling any pressure to merge this - don't. If you want it, that's cool, if you don't, that's cool too. Up to you!