add lookup path support to root component.json

[tj]

I cant find the issue now haha but @timoxley mentioned the env var as a development barrier. Instead of a default I think we could compromise and add support to the root component.json file to define lookup path(s) keeping it in your source. Potentially removing COMPONENT_PATH, I agree it's better to have this thing in source, I just dont want to go down the road of advocating what structure to use