Fix for RN 0.12

[elliottsj]

Fixes the problem where the RN packager would throw:

Error: Error validating module options: child "platform" fails because ["platform" is required]
    at /Users/spencerelliott/Dev/elliottsj/react-native-webpack-server/Examples/BabelES6/node_modules/react-native/packager/react-packager/src/lib/declareOpts.js:60:13
    at /Users/spencerelliott/Dev/elliottsj/react-native-webpack-server/Examples/BabelES6/node_modules/react-native/packager/react-packager/src/Server/index.js:161:20
    at tryCallOne (/Users/spencerelliott/Dev/elliottsj/react-native-webpack-server/Examples/BabelES6/node_modules/react-native/node_modules/promise/lib/core.js:37:12)
    at /Users/spencerelliott/Dev/elliottsj/react-native-webpack-server/Examples/BabelES6/node_modules/react-native/node_modules/promise/lib/core.js:103:15
    at flush (/Users/spencerelliott/Dev/elliottsj/react-native-webpack-server/Examples/BabelES6/node_modules/react-native/node_modules/promise/node_modules/asap/raw.js:50:29)
    at doNTCallback0 (node.js:407:9)
    at process._tickCallback (node.js:336:13)

Currently, hot module replacement is not working due to a recent change where the Chrome debugger now runs the app bundle inside a web worker: facebook/react-native#1632

[nevir]

Out of curiosity, what is missing from the web worker's environment that is required for HMR?

[elliottsj]

In the webpack config, we depend on webpack-dev-server/client.js to automatically update modules, but it depends on document.getElementsByTagName("script");, which throws an error in a web worker since there's no document. I haven't had the chance to investigate further than that though.