update Dockerfile

Author: junjun-zhang

helper-functions/Dockerfile

@@ -2,8 +2,8 @@ FROM ubuntu:20.04
 
 LABEL org.opencontainers.image.source https://github.com/icgc-argo/data-processing-utility-tools
 
-ENV PATH="/tools:${PATH}"
-
-COPY *.py /tools/
+RUN groupadd -g 1000 ubuntu &&\
+    useradd -l -u 1000 -g ubuntu ubuntu &&\
+    install -d -m 0755 -o ubuntu -g ubuntu /home/ubuntu
 
 CMD ["/bin/bash"]