Remove references to plugin in README
Remove references to plugin in README

This readme was largely shameless stolen from neturon and still
had reference to plugin path. This patch removes these references.

Change-Id: Iaf4171b18d7f62a8c830bc04ddd83b8d2b013b35

ramineni/my_congress,ramineni/my_congress,ekcs/congress,openstack/congress,ramineni/my_congress,ekcs/congress,openstack/congress,ekcs/congress,ramineni/my_congress,ekcs/congress