Openstack: Using VSPERF to Test on Openstack.

This patch will support running VSPERF Tests with Openstack.
This patch adds the following:
1. Provide --openstack parameter.
2. New Configuration file for openstack
3. Deploy Trafficgenerator based on configuration provided
4. Run Tests after Trafficgenerator are deployed on openstack

Update-1: Minor bug-fixes and Documentation Added.
Update-2: Add user-config to heat.
Update-3: Update Python Requirements
Update-4: Add dogpile
Update-5: Update decription of the Hot files.

Signed-off-by: Sridhar K. N. Rao <sridhar.rao@spirent.com>
Change-Id: Iebec356eb893e0e6726cac6a10537b99e41f67f4