updated factorial import for scipy version 0.10+
updated factorial import for scipy version 0.10+

anubhavvardhan/qutip,qutip/qutip,qutip/qutip,zasdfgbnm/qutip,anubhavvardhan/qutip,cgranade/qutip,cgranade/qutip,zasdfgbnm/qutip