Fixes
* Improve GitHub client to handle case where no public e-mail is available.
* Scope user:email is now required for this to work
* You should enable **Email addresses** permission in the **Permissions & events** section of your GitHub app parameters. You can find it at [https://github.com/settings/apps/{YOUR_APP}/permissions](https://github.com/settings/apps/{YOUR_APP}/permissions).
Improvements
* Bump dependencies:
* `httpx >=0.15,<0.18`