add testing instructions for sklearn server

sklearnserver/README.md

@@ -0,0 +1,39 @@
+## Testing instructions
+
+From the [upstream usage example](https://kserve.github.io/website/master/modelserving/v1beta1/sklearn/v2/#deploy-the-model-with-rest-endpoint-through-inferenceservice/), this rock can be tested locally using:
+
+Launch the server with:
+```
+# download the model locally
+gsutil cp -r gs://kfserving-examples/models/sklearn/1.0/model ./sample_model/
+
+# mount the model into the container at runtime
+docker run -p 8080:8080 -v $(pwd)/sample_model:/mnt/models sklearnserver:0.11.2 --model_name test_model --model_dir=/mnt/models --http_port=8080
+
+```
+
+Test the server with:
+```
+cat <<EOF >> iris-input-v2.json
+{
+  "inputs": [
+    {
+      "name": "input-0",
+      "shape": [2, 4],
+      "datatype": "FP32",
+      "data": [
+        [6.8, 2.8, 4.8, 1.4],
+        [6.0, 3.4, 4.5, 1.6]
+      ]
+    }
+  ]
+}
+EOF
+
+curl -v \
+  -H "Content-Type: application/json" \
+  -d @./iris-input-v2.json \
+  localhost:8080/v2/models/test_model/infer
+```
+
+which should return the expected output described in the docs.