VOL-4226: Bump minor version post voltha-2.8 release tagging

Change-Id: I7386eff39e4ffec8e938212c222170cd764d3a59
diff --git a/VERSION b/VERSION
index d5c0c99..86bab9c 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-3.5.1
+3.6.0-dev