I tried to re-generate the Protobuf/gRPC files, but generate.sh seems to
have assumed I manually built the Dockerfile ahead-of-time (unless I'm
missing something -- very possible). Unfortunately, when I went to do
that, I ended up with a handful of errors, most of them due to
differences in versions. (We probably want to think about pinning them.)
To remedy both issues, I've fixed up the Dockerfile so that it works for
me at least, and added a build step to the front of generate.sh.
