This commit also contains new code introduced after the PR in #853 was
merged. I just squashed it all together to prevent noisy commits to try
and fix CI.
The funny thing is that now the final commit looks fairly stupid/simple
but it wasn't that easy as I would have liked.
1. Couldn't find a proper way to execute `npm version` using yarn
workspaces. `yarn workspaces foreach npm version` would have worked
if we were using Yarn 2 instead of Yarn 1.
2. Introducing `version` and `publish` scripts in both packages worked,
but then the default `version` and `publish` were also executed.
3. Once I made the scripts unique (`npm-version`, `npm-publish`) it
worked~ish. The registry was always set to a yarnpkg registry, even
if we set the registry in CI and in a local .npmrc file. My guess is
that we are executing in a nested directory and therefore it didn't
work.
4. Next, I found the `npm workspaces` option so that we can use that in
addition to `yarn workspaces` 🙃
5. In CI of course this didn't work, because I was not using the same
node version...
6. After everything worked, I did cleanup of the new scripts, and
removed the introduced .npmrc files.