'Create `num_memberships` users and assign them to `team_id`. The
last user created becomes the current user.'

def create_memberships(self, num_memberships, team_id):

    memberships = []
    for __ in xrange(num_memberships):
        user_info = AutoAuthPage(self.browser, course_id=self.course_id).visit().user_info
        memberships.append(user_info)
        self.create_membership(user_info['username'], team_id)
    self.user_info = memberships[(-1)]
    return memberships
