Build development workflow for plugin and monorepo.

[atimmer]

Summary

In the monorepo setup we can longer set yoastseo/yoast-components to a GitHub URL in the package.json. This is problematic for trunk development. Locally, developers can use yarn link to develop, but that doesn't work for Travis or for building a zip.

Explanation

The plugin needs a command which does:

• Clone the monorepo, or fetch the latest version if that is currently not the case.
  • It should fetch the same branch as is currently checked out, with one exception: trunk should checkout develop in the monorepo.
• Run yarn link-all inside the monorepo.
• Run yarn link [package] for every package inside the Yoast SEO package.json that is scoped using @yoast.

Technical decisions

The command should also run on Travis.