webos-image-devel: add python to devel image

enable python is webos test package group for inclusion in the
development image

Open-webOS-DCO-1.0-Signed-off-by: Iyad Qumei <iyad.qumei@palm.com>

Change-Id: Ic6509142ced5f0ca99c1554f9f2b570a32b71e3a
Reviewed-on: https://g2g.palm.com/1904
Reviewed-by: Build Verification
Reviewed-by: Iyad Qumei <iyad.qumei@palm.com>
Tested-by: Iyad Qumei <iyad.qumei@palm.com>
Reviewed-by: Susan Montooth <susan.montooth@lge.com>