fix: add README badges (#6)

* feat: complete the redis adapter

* feat: add test cases

* feat: update readme

* ci: add semantic release

* ci: add semantic release

* ci: add semantic release

* ci: add semantic release

* feat: update readme

README.md

@@ -1,6 +1,14 @@
 Redis Adapter for PyCasbin 
 ====
 
+[![GitHub Actions](https://github.com/pycasbin/redis-adapter/workflows/build/badge.svg?branch=master)](https://github.com/pycasbin/redis-adapter/actions)
+[![Coverage Status](https://coveralls.io/repos/github/pycasbin/redis-adapter/badge.svg?branch=master)](https://coveralls.io/github/pycasbin/redis-adapter?branch=master)
+[![Version](https://img.shields.io/pypi/v/casbin_redis_adapter.svg)](https://pypi.org/project/casbin_redis_adapter/)
+[![PyPI - Wheel](https://img.shields.io/pypi/wheel/casbin_redis_adapter.svg)](https://pypi.org/project/casbin_redis_adapter/)
+[![Pyversions](https://img.shields.io/pypi/pyversions/casbin_redis_adapter.svg)](https://pypi.org/project/casbin_redis_adapter/)
+[![Download](https://img.shields.io/pypi/dm/casbin_redis_adapter.svg)](https://pypi.org/project/casbin_redis_adapter/)
+[![License](https://img.shields.io/pypi/l/casbin_redis_adapter.svg)](https://pypi.org/project/casbin_redis_adapter/)
+
 Redis Adapter is the [redis](https://redis.io/) adapter for [PyCasbin](https://github.com/casbin/pycasbin). With this library, Casbin can load policy from redis or save policy to it.
 
 ## Installation