Improve Docker start up script

- Make sure the last line contains the information
- Split in separate functions
- Add option to skip starting nginx (by default it is started)

docker/Dockerfile

@@ -11,9 +11,10 @@ COPY --chown=webgoat index.html /usr/share/nginx/html/
 COPY --chown=webgoat target/webgoat-server-*.jar /home/webgoat/webgoat.jar
 COPY --chown=webgoat target/webwolf-*.jar /home/webgoat/webwolf.jar
 COPY --chown=webgoat start.sh /home/webgoat
+RUN chmod +x /home/webgoat/start.sh
 
 EXPOSE 8080
 EXPOSE 9090
 
 WORKDIR /home/webgoat
-ENTRYPOINT /bin/bash start.sh
+ENTRYPOINT ["./start.sh"]