Bump minor version post VOLTHA2.4 branch out

Change-Id: Ie26f458f57dde470b2960b2f96a99a09a3cb05b8
diff --git a/VERSION b/VERSION
index c813fe1..b6bb93f 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.2.5
+1.3.0-dev