change tags for tempest plugins from master to mcp/pike

Change-Id: If7accada1c50a78826c63e0a94149c5b39842a0d
diff --git a/Dockerfile b/Dockerfile
index 160f399..a26565c 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -5,12 +5,12 @@
 ARG TEMPEST_TAG="mcp/pike"
 # Tempest plugins
 ARG HORIZON_TAG="mcp/pike"
-ARG BARBICAN_TAG="master"
+ARG BARBICAN_TAG="mcp/pike"
 ARG DESIGNATE_TAG="mcp/pike"
 ARG HEAT_TAG="mcp/pike"
-ARG IRONIC_TAG="master"
-ARG MANILA_TAG="master"
-ARG TELEMETRY_TAG="master"
+ARG IRONIC_TAG="mcp/pike"
+ARG MANILA_TAG="mcp/pike"
+ARG TELEMETRY_TAG="mcp/pike"
 # global openstack requirements repo
 ARG UPPER_CONSTRAINTS_TAG="stable/pike"
 #