Fixing windows issues

[wiggisser]

resolves #25

[apihlaja]

I don't think Windows build has to be a special case:

• use rimraf module instead of del and rm -rf.
• use webpack -p instead of NODE_ENV=production

Then it should works equally in win & *nix.

Edit: Hmm.. not sure if -p sets NODE_ENV to production. If that's not the case and the env var is needed, I think there is Webpack plugin for it.

[handrews]

It's been more than 3 months since changes were requested with no activity, so I'm closing this PR and copying the relevant comments to the issue.

Thanks for your efforts on this, everyone, we do still want to fix this and we will keep tracking it.