Upgrade React and Jest Presets

[johnthepink]

We are currently locked at react 15.4.0-rc2. Upgrading to 15.4.1 introduced an issue on the CI with importing "React" vs "react". See this comment.

Using the jest preset included in react-native since 0.38 actually fixed this issue, and cleaned up a lot of logging, but caused tests to fail that were making actual network requests, see this travis build

We should figure out the network issue and update react all the way.

[jbaxleyiii]

@johnthepink this should actually pretty really easy now that we are using jest. I'll try to mock those responses this weekend 👍

[johnthepink]

@jbaxleyiii oh sweet! I thought about doing that, but wasn't sure if we wanted the actual network requests.

[johnthepink]

I like mocking them better