Add balancer

Dockerfile

@@ -9,9 +9,7 @@ ENV BALANCER_CONFIG "/opt/data/config"
 # create a volume for the app
 VOLUME /opt/data
 
-COPY requirements.txt ./
+COPY balancer.py requirements.txt ./
 RUN pip install --upgrade pip && pip install --no-cache-dir -r requirements.txt
 
-COPY balancer.py ./
-
 CMD python ./balancer.py ${BALANCER_CONFIG} -nolog