Role isn't added, but everything else works

[sam-lord]

Describe the bug

When logging in with Google (after switching to test against my email domain), the role isn't added for the user.

Steps to reproduce

1. Fork, replace all instances of @netlify.com with my domain, and the netlify role with another.
2. Add a shared secret to both the webhook in the identity UI, and as an environment variable
3. Sign in with Google - taken to screen which says I have logged in, but not redirected to app

At this point, I checked the function log, and it is trying to assign the role, but nothing happens, no role is added.

Expected behavior

Role should have been added to user when logging in.

Can you submit a pull request?

I'd like to, but I haven't found any documentation for the identity webhooks. Is it supposed to return the user_metadata too? I've seen that shown on other code snippets on the web but haven't been able to determine what actually needs to happen.