Minor changes to Dockerfile

Dockerfile

@@ -5,11 +5,12 @@ USER user
 
 WORKDIR /app
 
-# Copy the application files into the container
-COPY app.py requirements.txt /app/
-
 RUN chown -R user:user /app
 
+# Copy the application files into the container
+COPY --chown=user:user requirements.txt /app/
+COPY --chown=user:user app.py /app/
+
 # Install dependencies
 RUN pip install --no-cache-dir --upgrade pip && \
     pip install --no-cache-dir -r requirements.txt