Add openstack-dev/sandbox groups for training
Add openstack-dev/sandbox groups for training

openstack-dev/sandbox repo uses different name in LP
(openstack-dev-sandbox).

Note that openstack-dev-sandbox LP has been
created for more practical upstream training exercises
for students with openstack-dev/sandbox repository.

Change-Id: Ied6b6604c1933e27c45417436106119fce99eb5b

Tesora/tesora-project-config,openstack-infra/project-config,openstack-infra/project-config,Tesora/tesora-project-config