Fixing docker automation issue

docker/2.1/Dockerfile

@@ -34,7 +34,7 @@ VOLUME /var/lib/mysql
 WORKDIR /mattermost
 
 # Copy over files
-ADD https://releases.mattermost.com/mattermost-team-2.1.0-rc1-linux-amd64.tar.gz
+ADD https://releases.mattermost.com/2.1.0-rc1/mattermost-team-2.1.0-rc1-linux-amd64.tar.gz /
 RUN tar -zxvf /mattermost-team-2.1.0-rc1-linux-amd64.tar.gz --strip-components=1 && rm /mattermost-team-2.1.0-rc1-linux-amd64.tar.gz
 ADD config_docker.json /
 ADD docker-entry.sh /