[VOL-4290] Voltha go library updates for gRPC migration

Change-Id: I1aa2774beb6b7ed7419bc45aeb53fcae8a8ecda0
diff --git a/vendor/github.com/golang/snappy/CONTRIBUTORS b/vendor/github.com/golang/snappy/CONTRIBUTORS
index 931ae31..d991473 100644
--- a/vendor/github.com/golang/snappy/CONTRIBUTORS
+++ b/vendor/github.com/golang/snappy/CONTRIBUTORS
@@ -28,7 +28,9 @@
 
 Damian Gryski <dgryski@gmail.com>
 Jan Mercl <0xjnml@gmail.com>
+Jonathan Swinney <jswinney@amazon.com>
 Kai Backman <kaib@golang.org>
+Klaus Post <klauspost@gmail.com>
 Marc-Antoine Ruel <maruel@chromium.org>
 Nigel Tao <nigeltao@golang.org>
 Rob Pike <r@golang.org>