VOL-3978 - update to go 1.16.3

Change-Id: I7a6ce8f823b7ea68ac446c43ca833e1d63a47779
diff --git a/docker/Dockerfile.openonu b/docker/Dockerfile.openonu
index 26b1c20..f65a9f9 100755
--- a/docker/Dockerfile.openonu
+++ b/docker/Dockerfile.openonu
@@ -15,10 +15,10 @@
 # -------------
 # Build stage
 
-FROM --platform=linux/amd64 golang:1.13.8-alpine3.11 AS dev
+FROM --platform=linux/amd64 golang:1.16.3-alpine3.13 AS dev
 
 # Install required packages
-RUN apk add --no-cache build-base=0.5-r1
+RUN apk add --no-cache build-base=0.5-r2
 
 # Use Standard go build directory structure
 WORKDIR /go/src