re-export the Classes
re-export the Classes

For example, so that we can get access to the `Me` constructor
via `import { Me } from 'wpcom'` instead of the current
way of `import Me from 'wpcom/build/lib/me'` which relies on
the implementation details of the `build` and `lib` dirs.

Automattic/wpcom.js,Automattic/wpcom.js