Update readme build badge for github actions
<img alt="micro logo" src="./assets/micro-logo-drop.svg" width="500px"/>
-[![Build Status](https://travis-ci.org/zyedidia/micro.svg?branch=master)](https://travis-ci.org/zyedidia/micro)
+![Test Workflow](https://github.com/zyedidia/micro/actions/workflows/test.yaml/badge.svg)
[![Go Report Card](https://goreportcard.com/badge/github.com/zyedidia/micro)](https://goreportcard.com/report/github.com/zyedidia/micro)
[![Release](https://img.shields.io/github/release/zyedidia/micro.svg?label=Release)](https://github.com/zyedidia/micro/releases)
[![MIT License](https://img.shields.io/badge/license-MIT-blue.svg)](https://github.com/zyedidia/micro/blob/master/LICENSE)
