Fix/react15 contract data not updating

[honestbonsai]

Fixes #4 #13

Note that this targets React 15 on master. Another one will be coming for React 16 on next.

You can test this by using drizzle-box and just changing accounts on Metamask. You should see the TutorialToken balance update correctly. Only Account 0 should have any balance.

Thanks to @carlosescom @Aare- for their original PRs

[adrianmcli]

lgtm

[samajammin]

Sweet! @honestbonsai just for my understanding - is there a roadmap to upgrade master to React 16? Or should I rely on next branch?

I opened an issue in this drizzle box that's related to the React versions across these projects: truffle-box/drizzle-box#77

[honestbonsai]

@sbrichards That's pretty much the next thing on my list to do. Going to try to port the changes from next into master.

master has received a number of fixes that next doesn't have, so need to work through those potential conflicts.

If you need React 16 support immediately, just use next branch. But I'm aiming to get this done soon. Thanks for your interest and support in drizzle-react-components!

[honestbonsai]

@sbrichards FYI refer to #63 if you want to provide some feedback on the new API for React 16.3 context components for v1.x.x.