Add Go version badge
![build](https://github.com/TwinProduction/gatus/workflows/build/badge.svg?branch=master)
[![Go Report Card](https://goreportcard.com/badge/github.com/TwinProduction/gatus?)](https://goreportcard.com/report/github.com/TwinProduction/gatus)
+[![Go version](https://img.shields.io/github/go-mod/go-version/TwinProduction/gatus.svg)](https://github.com/TwinProduction/gatus)
[![Docker pulls](https://img.shields.io/docker/pulls/twinproduction/gatus.svg)](https://cloud.docker.com/repository/docker/twinproduction/gatus)
A service health dashboard in Go that is meant to be used as a docker
