VOL-1381 and VOL-1091 Add feature to collect PMmetrics of OLT, this will collect Tx and Rx and posts to kafka. This commit is also related to changes of commit 72b25abd4e804596413558ef10f098c2262dd65d voltha-go
Updated review comments

Updated with code optimization
Updated with dep files
Updated fix for sanity test
Updated with gomod changes

Change-Id: I899e855812a6eda812c64664a9154321cdb16876
diff --git a/go.sum b/go.sum
index c92e136..a290f0e 100644
--- a/go.sum
+++ b/go.sum
@@ -190,8 +190,8 @@
 github.com/onsi/gomega v1.4.2/go.mod h1:ex+gbHU/CVuBBDIJjb2X0qEXbFg53c61hWP/1CpauHY=
 github.com/onsi/gomega v1.5.0 h1:izbySO9zDPmjJ8rDjLvkA2zJHIo+HkYXHnf7eN7SSyo=
 github.com/onsi/gomega v1.5.0/go.mod h1:ex+gbHU/CVuBBDIJjb2X0qEXbFg53c61hWP/1CpauHY=
-github.com/opencord/voltha-lib-go/v2 v2.2.7 h1:DMB1o9GubDeA9RhdYqcp5JbhQj7LpRohp+fBa9OY/x4=
-github.com/opencord/voltha-lib-go/v2 v2.2.7/go.mod h1:q/dYViCK5moxRVbHhrg31wyWz/rIfh9ze1fHO8rndX8=
+github.com/opencord/voltha-lib-go/v2 v2.2.8 h1:n0Cm6Gg2lIo7vyUosRRrsWrOzAbGr22H+JJlY6j+f0E=
+github.com/opencord/voltha-lib-go/v2 v2.2.8/go.mod h1:q/dYViCK5moxRVbHhrg31wyWz/rIfh9ze1fHO8rndX8=
 github.com/opencord/voltha-protos v1.0.3 h1:9v+R/QGF1xK+HKTqFM0IqCABoGCAxC8iKH4VzNBJDto=
 github.com/opencord/voltha-protos v1.0.3/go.mod h1:myfFIkJdA+rCXmKdLImhh79MfabN4ZOKQ4grk32DnPQ=
 github.com/pascaldekloe/goe v0.0.0-20180627143212-57f6aae5913c/go.mod h1:lzWF7FIEvWOWxwDKqyGYQf6ZUaNfKdP144TG7ZOy1lc=