Update `/me` endpoint for Microsoft accounts

[drewler]

https://github.com/closeio/sync-engine/blob/e19ff46f3ca8a1cb7fcfbdb6d0cc3cd10fe1a063/inbox/auth/microsoft.py#L37

Used in _get_user_info.

• Should use https://graph.microsoft.com/v1.0/me instead.
• Since the scope required (User.Read) is different from the ones in OAUTH_SCOPE, I suggest the following approach:
  • Override _get_user_info in MicrosoftAuthHandler, so it calls the parent method with a copy of session_dict where session_dict["access_token"] has been replaced with an access token with the right scope.
  • That access token (with User.Read scope) has to be requested just before calling the parent method, using the AuthAlligator client.

[drewler]

I think this URL is only used during the "Authorization Code" grant:

• Read from _get_user_info
  • Called from _get_authenticated_user
    • Called from interactive_auth
    • Called from inbox-auth script

Since this is not part of the main flow, updating this endpoint has lower priority and we can leave if for later.