Moving to onos 2.5.6 with karaf 4.2.14 and flow rule store fix

Change-Id: Ia310b19c099f57859099d4f4e4cacb4d4af36662
diff --git a/VERSION b/VERSION
index ab0fa33..f8ee15f 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-5.0.5
+5.1.0-dev