PEP8: Fixed most PEP8 issues in continous_variables.py
PEP8: Fixed most PEP8 issues in continous_variables.py

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