Support for babel@7

[szymonlesisz]

Hi, i'm not sure if this repo is maintained since last commit was a year ago.
I find it very useful to build from monorepo and i would like to use it with babel@7
Here's what i changed to make it work:

• update babel-file-loader package,
• remove unused babel-flow-types

[szymonlesisz]

Hi @jamiebuilds,
any updates on this? or should i publish my own fork to npm?

[toomuchdesign]

Hi you all, thanks for your amazing efforts, here.
Is there anything we can do to help shipping this PR?

Greetings!