Added test for max_calibrate method.
Added test for max_calibrate method.

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