added function serial_map to qutip.parallel, which has the same function signature as parallel_map and can easily be swapped with parallel_map
added function serial_map to qutip.parallel, which has the same function signature as parallel_map and can easily be swapped with parallel_map

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