Cleaned up the markdown formatting in RELEASENOTES.md.
Cleaned up the markdown formatting in RELEASENOTES.md.

briancurtin/pyrax,roelvv/pyrax,rackerlabs/heat-pyrax,rackspace/pyrax,sivel/pyrax,EdLeafe/pyrax,opsdisk/pyrax,emonty/pyos,0dataloss/pyrax,pratikmallya/pyrax,vikomall/pyrax,mandx/pyrax,naemono/pyrax,ddaeschler/pyrax