[VOL-2570]Update pyvoltha to use voltha-protos version 3.4.0

Change-Id: If43fd63ba7ae1af5aa98e022a496a24cde0e238c
diff --git a/VERSION b/VERSION
index 437459c..73462a5 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.5.0
+2.5.1
diff --git a/requirements.txt b/requirements.txt
index 13e69b3..e293cea 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -10,7 +10,7 @@
 jsonpatch==1.16
 netaddr==0.7.19
 pcapy==0.11.1
-protobuf==3.7.0
+protobuf==3.12.0
 python-consul==0.6.2
 scapy==2.4.3
 simplejson==3.12.0
@@ -18,4 +18,4 @@
 structlog==19.2.0
 transitions==0.6.4
 txaioetcd==0.3.0
-voltha-protos==3.3.9
+voltha-protos==3.4.0