Add endpoint to http-gateway for querying a single service
Add endpoint to http-gateway for querying a single service

Add `/services/:svc/:group/:org` endpoint to http-gateway in Supervisor.
This endpoint will return just the contents of a single service vs the
entire output of `/services`

Signed-off-by: Jamie Winsor <b4dde37aa2aac745c0e6c43447507eaeace3e59f@vialstudios.com>

rsertelon/habitat,georgemarshall/habitat,nathenharvey/habitat,rsertelon/habitat,habitat-sh/habitat,georgemarshall/habitat,habitat-sh/habitat,nathenharvey/habitat,habitat-sh/habitat,habitat-sh/habitat,georgemarshall/habitat,rsertelon/habitat,nathenharvey/habitat,rsertelon/habitat,georgemarshall/habitat,habitat-sh/habitat,habitat-sh/habitat,georgemarshall/habitat,habitat-sh/habitat,nathenharvey/habitat,rsertelon/habitat,georgemarshall/habitat,nathenharvey/habitat,georgemarshall/habitat,habitat-sh/habitat,rsertelon/habitat,georgemarshall/habitat,rsertelon/habitat,nathenharvey/habitat