Use babel-preset-env instead of 2015

[itsMapleLeaf]

Do you want to request a feature or report a bug?
Feature.

What is the current behavior?
The CLI initializes a project with the 2015 preset.

What is the expected behavior?
The CLI should use the env preset instead.

If this is a feature request, what is motivation or use case for changing the behavior?
It does the same as 2015, with additional fine-grained control for environment targets if the user cares to configure it. Also gets rid of the warning, bothersome or even confusing to some users.

I'd be happy to create a pull request for this 🙂

[evenstensberg]

Yep, totally agree @kingdaro ! A PR would be great! Hit me up if you need help getting to know the codebase. The preset & installation is here:

https://github.com/webpack/webpack-cli/blob/master/lib/creator/yeoman/webpack-generator.js#L111-L119

https://github.com/webpack/webpack-cli/blob/master/lib/creator/yeoman/utils/module.js

[evenstensberg]

It would be great if you PR this against my PR #194 , as there's a lot of changes in that one to the directory structure, but that's optional!

[itsMapleLeaf]

Done, made a pr against the feature/add branch. Hope I did it right 😄