Use published version of rework loader

Replace local copy of rework loader with @aaronj1335's new published
version, `rework-webpack-loader`.

https://github.com/aaronj1335/rework-webpack-loader
https://www.npmjs.org/package/rework-webpack-loader
Remove rework loader dependencies

We no longer need to track these dependencies since
`rework-webpack-loader` is its own package now.
Merge branch 'use-published-rework-loader'