Enable Source Maps for SCSS to CSS compilation

[fabinol]

Note to @markfinger poke around Google, there is something out there that solves the problem.

[fabinol]

Integrate build script from other projects + update package json.

[markfinger]

Have been poking around and investigating both the django-compressor and django-pipeline ecosystems. Unfortunately, both were architected at a time before source maps, so support requires a lot of hacks and poor outcomes due to implementation details.

An alternative solution - and possibly the optimal one - is to re-roll the necessary bits + pieces to integrate source maps. My instinct says to try and integrate with bits of compressor, but there are too many issues there, so I think this will be a path ending with a lot of code. In mildly exciting news, I've built a few asset pipelines + built tools in my time, so I could recycle a bunch of concepts and code snippets.

Not sure what the correct path to take is, as both will require a certain amount of time. Hacking around compressor/pipeline is probably the fastest path, but is also the riskiest as there are likely to be hidden implementation details that prevent achieving a satisfactory outcome. Rolling our own is likely to take longer, but is the safer path.

Will muse for a while...

[markfinger]

A third option I forgot, is to use an external build process built on webpack or gulp. This would be probably the sanest solution, but there are always a bunch of integration woes as the build process won't be able to introspect the python process easily. Unless you were to wrap the build process in a management command that populated env vars that the config read in.

Either way, will muse for a while...