Explicitly set `hashalg='sha512'`, in accordance with the [pyramid docs](http://docs.pylonsproject.org/projects/pyramid/en/latest/api/authentication.html#pyramid.authentication.AuthTktAuthenticationPolicy). Existing cookies will be invalidated, forcing one to login again (hopefully not a big deal).
Explicitly set `hashalg='sha512'`, in accordance with the
[pyramid docs](http://docs.pylonsproject.org/projects/pyramid/en/latest/api/authentication.html#pyramid.authentication.AuthTktAuthenticationPolicy).
Existing cookies will be invalidated, forcing one to login again (hopefully not a big deal).

ucsb-cs/submit,ucsb-cs/submit,ucsb-cs/submit,ucsb-cs/submit