frontend and backend Dockerfile for production not working

[蔡正海]

frontend build success but not working, the logs:

/usr/local/bin/docker-entrypoint.sh: line 4: nginx: not found

backend build error:

Service 'backend' failed to build : The command '/bin/sh -c npm install' returned a non-zero code: 228

[Chris Lee]

@forecho the issue has been resolved

#48