Automate docker image dependencies

[plotnick]

As originally discussed in #1211 and worked around in #1384, the current docker image build process requires manually adding new dependencies. It should get them from running tools/install_prerequisites.sh or some other mechanism (maybe a text file containing the names of dependencies?) so that we don't end up with silently broken images in the future.

[david-crespo]

We do run the prereqs script — the PR description on #1211 saying we don't do that was true when I initially posted it, then I fixed it in the PR and forgot to update the description.

omicron/Dockerfile

Line 23 in d1a99af

RUN tools/install_prerequisites.sh -y

But it sounds like it still wasn't working. Maybe we just need to add more things to the script.

[plotnick]

Hmmmmm, very interesting. I will do some further investigation, but it's no longer blocking CLI work since #1384 landed.