switch to use ceilometermiddleware

swift middleware contained in ceilometer is now deprecated. the
middleware is available in ceilometermiddleware.

Change-Id: I6e41986245f4d95a9385dc7829479ed1199f10ac
diff --git a/lib/ceilometer b/lib/ceilometer
index 9db0640..a464c52 100644
--- a/lib/ceilometer
+++ b/lib/ceilometer
@@ -322,6 +322,8 @@
     if use_library_from_git "ceilometermiddleware"; then
         git_clone_by_name "ceilometermiddleware"
         setup_dev_lib "ceilometermiddleware"
+    else
+        pip_install ceilometermiddleware
     fi
 }