Revert the tempest service name to marconi

This patch is to rollback the change introduced by
https://review.openstack.org/#/c/73100/. 73100 is no longer needed
because of the recent https://review.openstack.org/#/c/69497/.
Using 'marconi' as the service name will keep us aligned with the
naming convention used by other projects.

Change-Id: I5da6d2aaeb5c9dc29a1cbc70c8425449807eb34c
diff --git a/lib/marconi b/lib/marconi
index 0aaff1b..d1ab5f3 100644
--- a/lib/marconi
+++ b/lib/marconi
@@ -52,7 +52,7 @@
 MARCONICLIENT_BRANCH=${MARCONICLIENT_BRANCH:-master}
 
 # Tell Tempest this project is present
-TEMPEST_SERVICES+=,marconi-server
+TEMPEST_SERVICES+=,marconi
 
 
 # Functions