Modified README.md with newer example.
Modified README.md with newer example.

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