Generates a salt via pgcrypto.gen_salt('algorithm').

def salt(self):
        """
        Generates a salt via pgcrypto.gen_salt('algorithm').
        """
        cursor = connections[PGCRYPTOAUTH_DATABASE].cursor()
        cursor.execute("SELECT gen_salt('%s')" % PGCRYPTOAUTH_ALGORITHM)
        return cursor.fetchall()[0][0]