Minor PEP8 fixes.
Minor PEP8 fixes.

vivek425ster/pgmpy,ankurankan/pgmpy,sandeepkrjha/pgmpy,pratyakshs/pgmpy,jhonatanoliveira/pgmpy,pgmpy/pgmpy,jhonatanoliveira/pgmpy,kris-singh/pgmpy,pgmpy/pgmpy,pratyakshs/pgmpy,liquidmetal/pgmpy,sandeepkrjha/pgmpy,kris-singh/pgmpy,khalibartan/pgmpy,vivek425ster/pgmpy,anaviltripathi/pgmpy,kislayabhi/pgmpy,anaviltripathi/pgmpy,liquidmetal/pgmpy,palashahuja/pgmpy,palashahuja/pgmpy,yashu-seth/pgmpy,abinashpanda/pgmpy,ankurankan/pgmpy,khalibartan/pgmpy,kislayabhi/pgmpy,abinashpanda/pgmpy,yashu-seth/pgmpy