Multi UNI changes in voltha-lib-go

meterId setter method created for flows.

VERSION fixed

GetMeterIdFromWriteMetadata function added.
This function is used by rw-core when assigning meterId to upstream OLT trap flow.

Change-Id: Ic63735ae9006a68b364e703d58996cd3cee6049b
diff --git a/VERSION b/VERSION
index 0062ac9..6b244dc 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-5.0.0
+5.0.1