[Android]: Login does not return any promise

[xphaul]

@jodybrewster there is no data being logged after i have successfully logged in

[mlumbroso]

So, I had the same issue, it disappears when I change on the button

onPress={ this._login }

with

onPress={() => { this._login(); } }

Although there is the same error now with this, again a scope problem :
_this4._getUserProfile is not a function

[jodybrewster]

I'm going to start supporting promises soon, closing this for now