Merge pull request #60 from divy9881/change_status

fix: change casbin-cpp status.

Author: hsluoyz

README.md

@@ -26,8 +26,8 @@ production-ready | production-ready | production-ready | production-ready
 
 [![python](https://casbin.org/img/langs/python.png)](https://github.com/casbin/pycasbin) | [![dotnet](https://casbin.org/img/langs/dotnet.png)](https://github.com/casbin-net/Casbin.NET) | [![c++](https://casbin.org/img/langs/cpp.png)](https://github.com/casbin/casbin-cpp) | [![rust](https://casbin.org/img/langs/rust.png)](https://github.com/casbin/casbin-rs)
 ----|----|----|----
-[PyCasbin](https://github.com/casbin/pycasbin) | [Casbin.NET](https://github.com/casbin-net/Casbin.NET) | [casbin-cpp](https://github.com/casbin/casbin-cpp) | [Casbin-RS](https://github.com/casbin/casbin-rs)
-production-ready | production-ready | under-development | production-ready
+[PyCasbin](https://github.com/casbin/pycasbin) | [Casbin.NET](https://github.com/casbin-net/Casbin.NET) | [Casbin-CPP](https://github.com/casbin/casbin-cpp) | [Casbin-RS](https://github.com/casbin/casbin-rs)
+production-ready | production-ready | beta-test | production-ready
 
 ## Supported models