add module purchase_origin_address
split tests in travis
refactor the test of delivery address

Now setup is done in setUp, and the test methods contain only action +
assertion.
add myself to the contributors
remove checks: it is ignored on v8
Merge pull request #43 from yvaucher/8.0-add-purchase_origin_address

[8.0] add module purchase_origin_address
new module purchase_delivery_address

The new delivery address in the purchase order is propagated to
the picking.
mto dropshipping: propagate address so->po
travis: split purchase_delivery_address