upgrade yum cookbook version for python dependency
Make it safe to run vbox_update.sh with VMware boxes.
Backwards compatible syntax change to support Chef 11.
Merge pull request #280 from sudssm/unpin-yum

upgrade yum cookbook version
setup zookeeper on headnodes
setup cassandra on headnodes
setup redis on headnodes
get contrail up and running
replace nova-network with neutron
clean-up vars and other remainders from nova-network
no longer need ip forwarding enabled
partially remove floating vip
remove powerdns in contrail (addresses #255)