install root overlay before doing build scripts

Dockerfile

@@ -33,11 +33,11 @@ RUN \
     rm -rf /root/go && \
     rm /etc/ssh/*host*key*
 
+COPY ./root /
+
 COPY ./setup /tmp/setup
 RUN bash /tmp/setup/run.sh
 
-COPY ./root /
-
 RUN chmod +rx /etc/service/*/run
 
 CMD ["/usr/local/sbin/runsvinit"]