fix(publish): respect "pkg.publishConfig.directory"

[aleclarson]

This is a quick fix for #2113 (comment)

I assume you'll want to do it a different way :)

[evocateur]

Failing tests is a non-starter. What specific issue does this solve?

[aleclarson]

Failing tests is a non-starter.

Yeah sorry, I would fix/write tests if I had time.

What specific issue does this solve?

Running lerna publish does not respect pkg.publishConfig.directory when it filters the list of packages by their "privateness". It should be checking the package.json in the publish directory, instead. The package root is marked private to avoid accidental npm publish. When the publish directory has its package.json generated, the private: true field is removed.

[evocateur]

cc #2113 (comment)