Fully automate dev setup with Gitpod (#35)

* Fully automate dev setup with Gitpod

This commit implements a fully-automated development setup using Gitpod.io, an
online IDE for GitHub and GitLab that enables Dev-Environments-As-Code.
This makes it easy for anyone to get a ready-to-code workspace for any branch,
issue or pull request almost instantly with a single click.

* Update README.md

.gitpod.yml

@@ -0,0 +1,3 @@
+tasks:
+  - init: go get && go build ./... && go test ./...
+    command: go run

README.md

@@ -12,6 +12,7 @@ Faker requires Go >= 1.11
 [![Build Status](https://travis-ci.org/jaswdr/faker.svg?branch=master)](https://travis-ci.org/jaswdr/faker)
 [![Coverage Status](https://coveralls.io/repos/github/jaswdr/faker/badge.svg?branch=master)](https://coveralls.io/github/jaswdr/faker?branch=master)
 [![Go Report Card](https://goreportcard.com/badge/github.com/jaswdr/faker)](https://goreportcard.com/report/github.com/jaswdr/faker)
+[![Gitpod ready-to-code](https://img.shields.io/badge/Gitpod-ready--to--code-blue?logo=gitpod)](https://gitpod.io/#https://github.com/jaswdr/faker)
 
 ## Test it in Go Playground