DEV: ember-cli -u can be used to run a standalone dev discourse (PR #13336)

Previously we would need to launch unicorn separately this achieves the same goal by making 2 modifications:

  1. If -u is supplied ember-cli binary will launch and monitor ember cli and unicorn
  2. We suppress 200 requests to keep console clean (we may consider moving to development rails logs)

Also cleans out output a bit by supplying silent flags to yarn.


A commit that appears in this pull request is being discussed here.

oh oops … removing that, good catch!