Build: yarn install failed with an old version of yarn

[nb]

Steps to reproduce

1. Acquire an old version of yarn, in my case 0.22
2. Run yarn

What I expected

To update my dependencies.

What happened instead

I got an error Error: https://registry.yarnpkg.com/@automattic%2fbabel-plugin-transform-wpcalypso-async: Not found

After I updated yarn, it worked perfectly.

It wasn't a big deal, though it got me stumbled for a minute there If we can have a way to compare and enforce the yarn version in the engines field that would be awesome (very cursory Google search didn't show much).

[scinos]

Since yarn@1.0 (released ~2y ago) it will automatically pick the version declared in .yarnrc, which points to the latest version used in Calypso, 1.22.10

Since yarn@1.15.0 it also checks the engines field, that we specify as yarn: ^1.22.10