ci: Enhance verify and merge jobs

ci: Enhance verify and merge jobs

Verify and merge jobs will execute real vsperf TCs,
which won't require neither physical NICs nor traffic
generator. Script ./build-vsperf.sh will take care about
creation, update and activation of python virtual environment.
It will also install required system packages at nodes
running merge and verify jobs.
Additional improvements:
* set of simple sanity checks was added
* two new integration TCs were added; However test with
  VNF is not used now, because it requires a VM image.
* detailed logs are shown in case of failure

JIRA: VSPERF-391

Change-Id: I33e75e762fdc62656de92dc34f0ad7a484623603
Signed-off-by: Martin Klozik <martinx.klozik@intel.com>
Reviewed-by: Maryam Tahhan <maryam.tahhan@intel.com>
Reviewed-by: Al Morton <acmorton@att.com>
Reviewed-by: Christian Trautman <ctrautma@redhat.com>
Reviewed-by: Bill Michalowski <bmichalo@redhat.com>
Reviewed-by: Fatih Degirmenci <fatih.degirmenci@ericsson.com>