add tests for set_rule_for_parents
add tests for set_rule_for_parents

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