Bug fix: getToken for TG 3.x and username-password pair

[jamesmyatt]

/requesttoken has sightly different response using username-password pair. See https://docs.tigergraph.com/tigergraph-server/3.10/api/built-in-endpoints#_request_a_token

[jamesmyatt]

BTW, there's a lot of logic in getToken that could be refactored.

For example, if setToken is False, then you can bypass _token and just set apiToken to None directly. See

pyTigerGraph/pyTigerGraph/common/auth.py

Line 120 in 4ddaff6

else:

Also you can use _set_auth_header rather than duplicate the code in _parse_token_response.

[jamesmyatt]

Actually, _set_auth_header doesn't work when apiToken is a tuple!

[jamesmyatt]

@qe-tigergraph , can we get this bug fix merged?