Fix CDB running as root in docker container

Dockerfile

@@ -1,5 +1,8 @@
 FROM python:3.6
 
+RUN groupadd -g 5123 cdb && \
+    useradd -r -u 5123 -g cdb cdb
+
 WORKDIR /home/cdb
 
 COPY requirements.txt requirements.txt
@@ -10,3 +13,7 @@ COPY utils utils
 COPY app app
 COPY migrations migrations
 COPY config.cfg ./config.cfg
+
+RUN chown cdb:cdb /home/cdb -R
+
+USER cdb