VOL-4227: Bump minor version post voltha-2.8 release tagging

Change-Id: Iceb66ccf7ee70fe22f3164094ed517e14d95aa8d
diff --git a/VERSION b/VERSION
index 1892b92..c3f0d2b 100755
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.3.2
+1.4.0-dev