[ENHANCEMENT]: Update interpret to 2.0 (to have upward-optional for babel 7.0)

[ilan-schemoul]

Babel 7 now has a scope for the files it compiles which is determined by package.json.
I'll give my project as an example :

App/
  Client/
     Components/ 
      ...
      .babelrc
      package.json
      webpack.config.babel.js
   helpers/
      settings.js
  package.json

webpack.config.babel.js imports a file from outside /client "../helpers/settings.js"
With babel 6 it was okay, with babel 7 @babel/register must set "mode" to "upward-optional" (or upward) if you want babel to transpile files outside its root (which is determined by package.json).
So in my case importing a file outside from "client"

What is the expected behavior?
Being able to import from outside a folder with a package.json with babel 7.0
What is motivation or use case for adding/changing the behavior?
Babel 7 changed the behaviour, one needs to use upwad-optional/upward for babel 7.
How should this be implemented in your opinion?
Update to interpret to 2.0 (my PR brought upward-option for babel register of babel 7.0 gulpjs/interpret#58)

Are you willing to work on this yourself?
yes

[evenstensberg]

Could you submit a PR?

[ilan-schemoul]

215e233a updated the interpret. I don't see a release yet so I'm going to test against the next branch to test if I can finally do what I wanted to do (which mean use ESNext syntax like import/export in files imported from babel config files)

[ilan-schemoul]

Even installing webpack-cli from github, what I want to do still does not work. If I import from client/webpack.config.babel.js a file from outside client it won't parse the ES6 syntax through babel so export and import will fail.