Remove obsolete data dir from Dockerfile

Author: g3force

Dockerfile

@@ -17,7 +17,6 @@ RUN GOOS=linux GOARCH=amd64 packr build -o ../../release/ssl-game-controller_lin
 FROM alpine:3.9
 COPY --from=build_go /go/src/github.com/RoboCup-SSL/ssl-game-controller/release/ssl-game-controller_linux_amd64 /app/ssl-game-controller
 COPY config config
-RUN mkdir data
 EXPOSE 8081 10007 10008 10011 10009
 ENTRYPOINT ["/app/ssl-game-controller", "-address", ":8081"]
 CMD []