add csi-test to vendor

vendor/github.com/kubernetes-csi/csi-test/pkg/sanity/README.md

@@ -0,0 +1,62 @@
+# CSI Driver Sanity Tester
+
+This library provides a simple way to ensure that a CSI driver conforms to
+the CSI specification. There are two ways to leverage this testing framework.
+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).
+
+## 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
+Golang `TestXXX` functions. For example:
+
+```go
+func TestMyDriver(t *testing.T) {
+	// Setup the full driver and its environment
+	... setup driver ...
+	config := &sanity.Config{
+		TargetPath:     ...
+		StagingPath:    ...
+		Address:        endpoint,
+	}
+
+
+	// Now call the test suite
+	sanity.Test(t, config)
+}
+```
+
+Only one such test function is supported because under the hood a
+Ginkgo test suite gets constructed and executed by the call.
+
+Alternatively, the tests can also be embedded inside a Ginkgo test
+suite. In that case it is possible to define multiple tests with
+different configurations:
+
+```go
+var _ = Describe("MyCSIDriver", func () {
+	Context("Config A", func () {
+		var config &sanity.Config
+
+		BeforeEach() {
+			... setup driver and config...
+		}
+
+		AfterEach() {
+			...tear down driver...
+		}
+
+		Describe("CSI sanity", func() {
+			sanity.GinkgoTest(config)
+		})
+	})
+
+	Context("Config B", func () {
+		...
+	})
+})
+```
+
+## Command line program
+Please see [csi-sanity](https://github.com/kubernetes-csi/csi-test/tree/master/cmd/csi-sanity)