update to install libzbar0

Dockerfile

@@ -2,10 +2,15 @@ FROM python:3.9
 
 WORKDIR /code
 
-COPY ./requirements.txt /code/requirements.txt
+# environment
+RUN apt-get update \
+    && apt-get install -y libzbar0 \
+    && apt-get clean \
+    && rm -rf /var/lib/apt/lists/*
 
+# python library
+COPY ./requirements.txt /code/requirements.txt
 RUN pip install --no-cache-dir --upgrade -r /code/requirements.txt
-RUN sudo apt-get install libzbar0
 
 COPY . .