Remove unused six import.
Remove unused six import.

audreyr/binaryornot,0k/binaryornot,hackebrot/binaryornot,pombredanne/binaryornot,hackebrot/binaryornot,pombredanne/binaryornot,hackebrot/binaryornot,pombredanne/binaryornot,audreyr/binaryornot,audreyr/binaryornot,0k/binaryornot