npm run icon-gen and grunt (run default task) can be grouped into one
operation.
Use SIGNAL_ENV instead of NODE_ENV since Setting NODE_ENV adversely
affects yarn's install behavior, so we had to set it after the install
and before the build. By using a custom variable instead, we can set it
globally and eventually use it in a build matrix.
Move mas build to its own npm script
// FREEBIE
These modules together allow us to import css files from third party
components without maintaining symlinks that essentially rename them as
sass partials, which doesn't work on windows.
// FREEBIE
