pin upstream bazel to 0.24 - #210

Thanks! Pinning the bazel version is probably a good idea even if we want to keep compatibility with the bleeding edge. Will merge later today.

Thinking about this more, I don't think we need to change from the apt repo to wgetting the install script. It looks like old versions are not pruned from the bazel-apt package source, so that should still be viable, plus it avoids needing to manually install dependencies (beyond openjdk, as described on the install page).

I'll see if pinning it in the install line works, then maybe refactor this file a bit.

Turns out we don't keep old versions around in our apt repo after all, despite the fact that the files themselves are still present and reported in the XML page at the apt's URL. Oh well.

The other options someone suggested were

• wgetting the binary and running it directly without installation, or

• using bazelisk

I think your approach is simpler.