With the introduction of RFC 176 Ember moved towards import paths prefixed with @ember/ which ultimately should use the @ember scope on npm. This gives us a better indicator of a project being official or a community-project. Since ember-test-helpers is an official project it might make sense to move it to @ember/test-helpers too.

emberjs/rfcs#268 is introducing a public API for this package for the first time so we should probably decide this until the RFC lands.

/cc @rwjblue