Improve Dockerfile

[fchavant]

Expected behavior

• Use COPY --chown (commented out in the past because of older version of the docker engine
• Use npm ci instead of npm install
• Check whether bower is needed
• Check whether nasm is needed

Actual behavior

COPY --chown was commented out in the past because of older version of the docker engine on cloud.docker.com; bower and nasm look like cruft.

Steps to reproduce

Build docker image.