standardize packaging, tooling, docs, CI, and licensing

mail_intake/auth/google.py

@@ -17,12 +17,12 @@ No Google authentication details should leak outside this module.
 """
 
 import os
-from typing import Sequence
+from collections.abc import Sequence
 
 import google.auth.exceptions
 from google.auth.transport.requests import Request
-from google_auth_oauthlib.flow import InstalledAppFlow
 from google.oauth2.credentials import Credentials
+from google_auth_oauthlib.flow import InstalledAppFlow
 
 from mail_intake.auth.base import MailIntakeAuthProvider
 from mail_intake.credentials.store import CredentialStore