IS-364: Bump golang build image. (#14134)

* IS-364: Bump Golang CI.

* Fix test failure

* Fix readme

* Update build/README.md

Co-authored-by: Agniva De Sarker <agnivade@yahoo.co.in>

build/Dockerfile.buildenv

@@ -1,3 +1,3 @@
-FROM golang:1.13
+FROM golang:1.14.1
 
 RUN apt-get update && apt-get install -y make git apt-transport-https ca-certificates curl software-properties-common build-essential zip xmlsec1 jq