add: demo server and client

demo_server/Dockerfile

@@ -0,0 +1,16 @@
+FROM python:3-alpine
+
+RUN mkdir -p /usr/src/app
+WORKDIR /usr/src/app
+
+COPY requirements.txt /usr/src/app/
+
+RUN pip3 install --no-cache-dir -r requirements.txt
+
+COPY . /usr/src/app
+
+EXPOSE 8080
+
+ENTRYPOINT ["python3"]
+
+CMD ["-m", "openapi_server"]