tests: move common funtion definitions to include.rc

Change-Id: I3526557d0a675692e94edb71b7d92c9202e6afa4
BUG: 765473
Signed-off-by: Raghavendra G <raghavendra@gluster.com>
Reviewed-on: http://review.gluster.org/4559
Reviewed-by: Amar Tumballi <amarts@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>