refactor dockerfile

Author: zarbis

Dockerfile

@@ -6,6 +6,7 @@ RUN apt-get update && \
 
 RUN curl -s https://packagecloud.io/install/repositories/github/git-lfs/script.deb.sh | bash && \
     apt-get install git-lfs=3.5.1 && \
+    apt-get clean && \
     git lfs install
 
 # USER nodeuser