Bumping version after 2.7 release

Change-Id: I491243d8584b87541b25d0d419b5db2570e1764b
diff --git a/VERSION b/VERSION
index 24ba9a3..9781df7 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.7.0
+2.8.0-dev