Update SD-Core document for release 1.2

Change-Id: Id0a3c93df5ca79b594a330e7c3fb040b5a47113e
diff --git a/VERSION b/VERSION
index 26aaba0..538ee20 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.2.0
+1.2.1-dev