fix: the coverage baddge link is incorrect (#11)

Author: LinuxSuRen

README.md

@@ -1,5 +1,5 @@
 [![Codacy Badge](https://app.codacy.com/project/badge/Grade/3f16717cd6f841118006f12c346e9341)](https://www.codacy.com/gh/LinuxSuRen/api-testing/dashboard?utm_source=github.com&utm_medium=referral&utm_content=LinuxSuRen/api-testing&utm_campaign=Badge_Grade)
-[![Codacy Badge](https://app.codacy.com/project/badge/Coverage/5022a74d146f487581821fd1c3435437)](https://www.codacy.com/gh/LinuxSuRen/api-testing/dashboard?utm_source=github.com&utm_medium=referral&utm_content=LinuxSuRen/api-testing&utm_campaign=Badge_Coverage)
+[![Codacy Badge](https://app.codacy.com/project/badge/Coverage/3f16717cd6f841118006f12c346e9341)](https://www.codacy.com/gh/LinuxSuRen/api-testing/dashboard?utm_source=github.com&utm_medium=referral&utm_content=LinuxSuRen/api-testing&utm_campaign=Badge_Coverage)
 ![GitHub All Releases](https://img.shields.io/github/downloads/linuxsuren/api-testing/total)
 
 This is a API testing tool.