Should SessionIdentityPolicy.remember call new_session instead of get_session?

Hi,

The SessionIdentityPolicys `remember` method calls aiohttp_sessions [get_session](https://github.com/aio-libs/aiohttp-security/blob/master/aiohttp_security/session_identity.py#L30) but the aiohttp_session docs state to always use [new_session](https://aiohttp-session.readthedocs.io/en/stable/reference.html#aiohttp_session.new_session) for logins - is that not what `remember` is mostly be used in, login views?