added build & push

postfix/Dockerfile

@@ -10,7 +10,6 @@ apt-get autoclean
 rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* ~/.cache ~/.npm
 EOF
 COPY etc/postfix/ /etc/postfix/
-RUN cp /etc/resolv.conf /var/spool/postfix/etc/resolv.conf
 COPY --chmod=0775 entrypoint.sh /entrypoint.sh
 EXPOSE 25
 VOLUME /var/spool/postfix