VOL-1371 Allow specifying versions of onos apps

Also bump VERSION

Change-Id: I602e80a73200a11f75ea5e00a939ecd2f63a2abc
diff --git a/VERSION b/VERSION
index dfda3e0..f67d718 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-6.1.0
+6.2.0-dev