Add oslo.policy to lib/oslo and stackrc

As per the graduation work items, any new libraries should be
added to lib/oslo and stackrc

partially implements bp graduate-policy

Change-Id: Ief8f28715ecff5a602d6d840d736ea07b5e7ff39
diff --git a/stackrc b/stackrc
index 42a625b..96e6a70 100644
--- a/stackrc
+++ b/stackrc
@@ -341,6 +341,10 @@
 GITREPO["oslo.middleware"]=${OSLOMID_REPO:-${GIT_BASE}/openstack/oslo.middleware.git}
 GITBRANCH["oslo.middleware"]=${OSLOMID_BRANCH:-master}
 
+# oslo.policy
+GITREPO["oslo.policy"]=${OSLOPOLICY_REPO:-${GIT_BASE}/openstack/oslo.policy.git}
+GITBRANCH["oslo.policy"]=${OSLOPOLICY_BRANCH:-master}
+
 # oslo.rootwrap
 GITREPO["oslo.rootwrap"]=${OSLORWRAP_REPO:-${GIT_BASE}/openstack/oslo.rootwrap.git}
 GITBRANCH["oslo.rootwrap"]=${OSLORWRAP_BRANCH:-master}