reverting change to dockerfile (#1594)

Signed-off-by: Adrian Sutton <adrian.sutton@consensys.net>

docker/Dockerfile

@@ -1,6 +1,10 @@
 FROM openjdk:11.0.2-jre-slim-stretch
 
-COPY pantheon /opt/pantheon/
+COPY pantheon-*.tar.gz /tmp/.
+RUN tar xzf /tmp/pantheon-*.tar.gz -C /tmp && \
+  rm /tmp/pantheon-*.tar.gz && \
+  mv /tmp/pantheon-* /opt/pantheon
+
 
 RUN mkdir /var/lib/pantheon
 RUN mkdir /etc/pantheon/