add blazeface

python/examples/blazeface/README.md

+# Blazeface 
+
+## Get Model
+```
+python -m paddle_serving_app.package --get_model blazeface
+tar -xzvf blazeface.tar.gz
+```
+
+## RPC Service
+
+### Start Service
+
+```
+python -m paddle_serving_server.serve --model serving_server --port 9494
+```
+
+### Client Prediction
+
+```
+python test_client.py serving_client/serving_client_conf.prototxt test.jpg
+```
+
+the result is in `output` folder, including a json file and image file with bounding boxes.