Mastodon tests fail: need different way of obtaining API token

[jernst]

Since this was originally implemented, Mastodon has removed OAuth Resource Owner Password Credentials, which means our way of obtaining an API token is no longer viable. So all Mastodon-related tests that require the use of the API (i.e. all non-Webfinger tests) fail.

We need to find a different automatable avenue and implement that.

[jernst]

Maybe we could run something like this and get the token from a script run on the Mastodon-under-test server.

token = Doorkeeper::AccessToken.create!(
  application: app,
  resource_owner_id: user.id,
  scopes: "read write follow push")