fix Dockerfile to copy models folder

flask_api/web/Dockerfile

@@ -1,7 +1,11 @@
 FROM continuumio/miniconda
 LABEL maintainer="Peng Xiao<xiaoquwl@gmail.com>"
 
-COPY . /
+RUN mkdir /opt/app
+
+COPY . /opt/app
+
+ADD models /opt/app/models
 
 RUN pip install -r requirements.txt && pip install gunicorn