React native support

[tonyxiao]

Logdown doesn't seem to work in react native by default. This is my workaround

import 'localstorage-polyfill'
import { defaults } from 'lodash'
// https://github.com/caiogondim/logdown.js
localStorage.debug = __DEV__ ? '*' : false
// TODO: Make logdown recognize react-native properly
/**
 * Get color working in logdown
 * https://github.com/caiogondim/logdown.js/blob/master/src/util/is-color-supported/browser.js
 */
defaults(window, {
  document: {
    documentElement: {
      style: {
        WebkitAppearance: '',
      },
    },
  },
})

Would be great if it's officially supported.

[caiogondim]

Thanks for the report.
I'll work on it.