Support setting colors with a .hues.yml file
As seen in !3 (merged), people might have different expectations with the colors.
It would be nice to have a default
.hues.yml file in the
spiro-deploy repo, which can be overriden by
_salt/.hues.yml (for example?) in the repo being deployed, but the
hues documentation is mostly inexistent so I don't know how to go about that.