Update README.md

pkg/sanity/README.md

@@ -6,6 +6,15 @@ For CSI drivers written in Golang, the framework provides a simple API function
 to call to test the driver. Another way to run the test suite is to use the
 command line program [csi-sanity](https://github.com/kubernetes-csi/csi-test/tree/master/cmd/csi-sanity).
 
+## Status
+Although the project can be used immediately, it will not provide full
+coverage since it is not yet finished. Below shows the percentage of
+completion for each CSI service:
+
+* Identity Service: 95%
+* Controller Service: 0%
+* Node Service: 0%
+
 ## For Golang CSI Drivers
 This framework leverages the Ginkgo BDD testing framework to deliver a descriptive
 test suite for your driver. To test your driver, simply call the API in one of your