update go version

Dockerfile

@@ -1,4 +1,4 @@
-ARG GO_VERSION=1.15.2
+ARG GO_VERSION=1.16.2
 FROM golang:${GO_VERSION}-alpine AS builder
 RUN apk update && apk add alpine-sdk git && rm -rf /var/cache/apk/*
 RUN mkdir -p /api

server/go.mod

@@ -1,6 +1,6 @@
 module github.com/akhilrex/hammond
 
-go 1.15
+go 1.16
 
 require (
 	github.com/dgrijalva/jwt-go v3.2.0+incompatible