Add proper windows support.

[arunoda]

Seems like we use some bash features. See: #145
We need to add some proper support for windows.

cc @mnmtanish

[thani-sh]

I think we can use shelljs to write scripts so it'll work on all platforms. Eg. prepublish.js instead of prepublish.sh.

I'm working on integrating Appetize.io to react-native-storybook these days. I'll get back to react-storybook as soon as it's ready.

[arunoda]

@mnmtanish sounds like a good plan.

[szopenkrk]

Its possible to fix that soon ?

[wallslide]

It's working for me on Windows now. Thanks!

[thani-sh]

Fixed with #308