vswitchperf: Update merge and verify jobs

vswitchperf: Update merge and verify jobs

Update and verify jobs will execute real vsperf TCs,
which won't require a traffic generator. Script
./build-vsperf.sh will take care about creation, update
and activation of python virtual environment. Jobs will
be executed at ubuntu nodes, where python3 is available,
so call of scl is required only for daily job. Update
is backward compatible, i.e. merge and verify jobs
will pass with old version of ./build-vsperf.sh.

JIRA: VSPERF-391

Change-Id: I6cb0e9a1c1bcf315dd0e484f845123ec41c849fc
Signed-off-by: Martin Klozik <martinx.klozik@intel.com>
Reviewed-by: Fatih Degirmenci <fatih.degirmenci@ericsson.com>