Add react 15 support

[levithomason]

React 15 was released a couple weeks ago. Basic use of react-ace seems to work OK, however, it is throwing a peerDep error:

› npm ls react
PROJECT @0.0.1 /My/system/path
`-- UNMET PEER DEPENDENCY react@15.0.1

npm ERR! peer dep missing: react@^0.13.0 || ^0.14.0, required by react-ace@3.2.0
npm ERR! code 1

[securingsincity]

3.3.0 resolves this issue

[levithomason]

Confirmed, thanks a bunch!