Sort out package.json dev and prod dependencies
Sort out package.json dev and prod dependencies

This moves the things in the prod dependencies
That are not actually needed for brandable_css
Previews to generate to the devDependencies

Test plan:
rm -rf node_modules yarn.lock
yarn install --production
yarn run brandable_css

All your css should generate without errors

Change-Id: I68bc3aeaf4b8ac934cdd3372476795a062cdcc69
Reviewed-on: https://gerrit.instructure.com/112514
Reviewed-by: Jon Jensen <44f878afe53efc66b76772bd845eb65944ed8232@instructure.com>
Product-Review: Jon Jensen <44f878afe53efc66b76772bd845eb65944ed8232@instructure.com>
QA-Review: Jon Jensen <44f878afe53efc66b76772bd845eb65944ed8232@instructure.com>
Tested-by: Jenkins

instructure/canvas-lms,sfu/canvas-lms,venturehive/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,venturehive/canvas-lms,instructure/canvas-lms,djbender/canvas-lms,djbender/canvas-lms,venturehive/canvas-lms,djbender/canvas-lms,sfu/canvas-lms,venturehive/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,djbender/canvas-lms,sfu/canvas-lms,sfu/canvas-lms