variables.css isn't exported in build

[ggascoigne]

The file src/styles/variables.css is striped of everything interesting by the build, if it was copied over intact then client css or scss could import it directly. This would make it easier for client apps to share constants.

[andrewleyva]

I'm of the opinion that we should refactor this to be LESS (and then still export the variables file). But that's probably out of scope for this.

[ggascoigne]

I don't particularly mind about the refactoring, I just want a css or sccs compatible file (like the original one that's checked in), that I can import directly into my code.

Truth be told a sccs file would be more useful, so maybe exposing both flavors would be nice, since sccs gives a deprecation warning if you import a css file.