Remove es2015-loose, es2015-no-commonjs, etc with Babel 6.13.x

[Daniel15]

See discussion in #42 (comment)

From @taion:

The 6.13.x API actually moots es2015-loose, es2015-no-commonjs, &c. – might be worth cutting a breaking release that just drops those and has just es2015? That'd take the major version out of sync with Babel itself, though.

[taion]

It depends how closely you want to follow semver. Probably it would be more confusing than it'd be worth for the version of babel-standalone tracking Babel 6.13.x to be 7.0.0.

But it is really nice to just write

["es2015", { "modules": false }]
["es2015", { "loose": true }]

&c.

[Daniel15]

I want to keep the version number equal to Babel's.

[Jessidhia]

This depends on #49

[taion]

Probably the only thing we can do here is to deprecate those, if we want to keep semver.

[hzoo]

Ok we can do this easily (in the monorepo), just substitute it out (refactor) for now