Ability to set lock_path

PROD-34037

Change-Id: I35fbd0acb5f5a09f2a8070ebe32c30e09fdac747
diff --git a/README.rst b/README.rst
index 07bd013..456fc74 100644
--- a/README.rst
+++ b/README.rst
@@ -32,6 +32,8 @@
             enabled: True
           qcow2:
             enabled: True
+        concurrency:
+          lock_path: '/var/lib/glance/tmp'
         policy:
           publicize_image:
             - "role:admin"