move into /app dir and add new db handler + wrappers

Dockerfile

@@ -11,7 +11,7 @@ COPY requirements.txt .
 RUN pip install --no-cache-dir -r requirements.txt
 
 # Copy the server code into the container
-COPY server.py .
+COPY ./app .
 
 # Make port 8765 available to the world outside this container
 EXPOSE 8765