Use keystone v3 API for projects

Always use the keystone v3 API for project creation. Make domain a
required argument. Whilst we could simply default this value within the
function I think it's better to make this explicit as these are things
deployers and services need to consider.

In future we will want to figure out how we want devstack to organize domains
however I don't believe that it belongs in this patch.

Change-Id: Ib9587193c5c8419dc4b5a608246709baaddd2a52
Implements: bp keystonev3
diff --git a/lib/tempest b/lib/tempest
index c4ae05f..4e7133a 100644
--- a/lib/tempest
+++ b/lib/tempest
@@ -546,7 +546,7 @@
     if is_service_enabled tempest; then
         # Tempest has some tests that validate various authorization checks
         # between two regular users in separate tenants
-        get_or_create_project alt_demo
+        get_or_create_project alt_demo default
         get_or_create_user alt_demo "$ADMIN_PASSWORD" "alt_demo@example.com"
         get_or_add_user_project_role Member alt_demo alt_demo
     fi