React fiber compatibility

[rafeca]

This PR adds compatibility to the new React Fiber data structure. This fixes hot module reloading in React Native for React v16.

I've done the change in the 1.x branch, since this is the one used by the react-proxy module, which is used for HMR, but a very similar PR can be done for v2.

The tests haven't been changed, to ensure the backwards compatibility, but I have a commit which updates React to v16 to prove that this works on React Fiber (rafeca@2eb66a9).

Ideally we should have tests for different versions of React, but this is out of scope of this PR :)

[rafeca]

@gaearon I've had to update a few dependencies in order to get the build passing:

• I've updated mocha-jsdom and addedd jsdom dependency fixed to v7 (to workaround TypeError: require(...).env is not a function rstacruz/mocha-jsdom#27).
• I've updated babel-eslint to v4, (to workaround TypeError: Cannot read property 'visitClass' of undefined babel/babel-eslint#243).
• I've changed the travisCI config to use Node.js v6 (the current active LTS version). This fixes some weird issues with mocha-jsdom and io.js (see the output of https://travis-ci.org/gaearon/react-deep-force-update/builds/262371539).

[gaearon]

Thanks!

[gaearon]

All released. Thank again!