build: add github ci status badge

README.md

@@ -5,6 +5,7 @@
 [![Maintainability](https://api.codeclimate.com/v1/badges/d5a5e060522403b1f79b/maintainability)](https://codeclimate.com/github/phodal/coca/maintainability)
 [![codecov](https://codecov.io/gh/phodal/coca/branch/master/graph/badge.svg)](https://codecov.io/gh/phodal/coca)
 ![GitHub go.mod Go version](https://img.shields.io/github/go-mod/go-version/phodal/coca)
+![Go](https://github.com/phodal/coca/workflows/Go/badge.svg)
 
 > [Coca](https://coca.migration.ink/) is a toolbox which is design for legacy system refactoring and analysis, includes call graph, concept analysis, api tree, design patterns suggest.
 [Coca](https://coca.migration.ink/) 是一个用于系统重构、系统迁移和系统分析的瑞士军刀。它可以分析代码中的 badsmell，行数统计，分析调用与依赖，进行 Git 分析，以及自动化重构等。