Add devstack-version script

This will help in collecting information about the devstack version
being used.

Change-Id: I23a8ca023bda6d097051cd57ae45401806451ad5
diff --git a/stackrc b/stackrc
index 50f7c89..5da9a2a 100644
--- a/stackrc
+++ b/stackrc
@@ -272,6 +272,7 @@
 # Setting the variable to 'ALL' will activate the download for all
 # libraries.
 
+DEVSTACK_SERIES="pike"
 
 ##############
 #