Add oslo.cache to devstack

as part of the graduation process, add oslo.cache to lib/oslo
and stackrc.

Change-Id: I2baf0384dd5d71d234a95b7acd0bfe5534f2732c
diff --git a/lib/oslo b/lib/oslo
index 554bec8..be935bb 100644
--- a/lib/oslo
+++ b/lib/oslo
@@ -26,6 +26,7 @@
 GITDIR["cliff"]=$DEST/cliff
 GITDIR["debtcollector"]=$DEST/debtcollector
 GITDIR["futurist"]=$DEST/futurist
+GITDIR["oslo.cache"]=$DEST/oslo.cache
 GITDIR["oslo.concurrency"]=$DEST/oslo.concurrency
 GITDIR["oslo.config"]=$DEST/oslo.config
 GITDIR["oslo.context"]=$DEST/oslo.context
@@ -66,6 +67,7 @@
     _do_install_oslo_lib "cliff"
     _do_install_oslo_lib "debtcollector"
     _do_install_oslo_lib "futurist"
+    _do_install_oslo_lib "oslo.cache"
     _do_install_oslo_lib "oslo.concurrency"
     _do_install_oslo_lib "oslo.config"
     _do_install_oslo_lib "oslo.context"