Update Dockerfile

Dockerfile

@@ -7,8 +7,9 @@ WORKDIR /code
 # Copy the current directory contents into the container at /usr/src/app
 COPY . .
 
-# Install any needed packages specified in requirements.txt
-RUN pip install -r requirements.txt
+COPY ./requirements.txt /code/requirements.txt
+
+RUN pip install --no-cache-dir --upgrade -r /code/requirements.txt
 
 # Make port 8000 available to the world outside this container
 EXPOSE 8000