Use nova client to erase sec groups
Use nova client to erase sec groups

Add usage of nova client to erase created security groups

Change-Id: I51f25f890a167007f715ea774ac6a2346c0acbd6
Closes-Bug: 1447596

mcloudv/fuel-ostf,stackforge/fuel-ostf,eayunstack/fuel-ostf,stackforge/fuel-ostf,mcloudv/fuel-ostf,eayunstack/fuel-ostf