createrapid.py is now using heat templates yaml

createrapid.py is now using heat templates yaml

yaml files have been added to the repo as an example. Please check the
README explaining the output section reqs for this yaml file. There is
also a new file (config_file): it also specifies which yaml files to
use. multiple dataplane interfaces per VM can now be specified and will
appear in the <STACK>.env file. An error in setting the packet size has
been fixed (see set_udp_packet_size for packet size setting details)

Change-Id: Ie89a4940521dac7dd3652acca477739abb9f5497
Signed-off-by: Luc Provoost <luc.provoost@intel.com>