[Serving] Simple serving YOLOv5 and PP-OCRv3 example, add uvicorn to fastdeploy tools (#986)

* ppocrv3 simple serving

* add uvicorn to fd tools

* update ppdet simple serving readme

* yolov5 simple serving

* not import simple serving by default

* remove config from envs

* update comment

examples/vision/detection/yolov5/python/serving/server.py

@@ -0,0 +1,38 @@
+import fastdeploy as fd
+from fastdeploy.serving.server import SimpleServer
+import os
+import logging
+
+logging.getLogger().setLevel(logging.INFO)
+
+# Configurations
+model_dir = 'yolov5s_infer'
+device = 'cpu'
+use_trt = False
+
+# Prepare model
+model_file = os.path.join(model_dir, "model.pdmodel")
+params_file = os.path.join(model_dir, "model.pdiparams")
+
+# Setup runtime option to select hardware, backend, etc.
+option = fd.RuntimeOption()
+if device.lower() == 'gpu':
+    option.use_gpu()
+if use_trt:
+    option.use_trt_backend()
+    option.set_trt_input_shape("images", [1, 3, 640, 640])
+    option.set_trt_cache_file('yolov5s.trt')
+
+# Create model instance
+model_instance = fd.vision.detection.YOLOv5(
+    model_file,
+    params_file,
+    runtime_option=option,
+    model_format=fd.ModelFormat.PADDLE)
+
+# Create server, setup REST API
+app = SimpleServer()
+app.register(
+    task_name="fd/yolov5s",
+    model_handler=fd.serving.handler.VisionModelHandler,
+    predictor=model_instance)