added CanonicalFactor.reduce
added CanonicalFactor.reduce

jhonatanoliveira/pgmpy,khalibartan/pgmpy,abinashpanda/pgmpy,pgmpy/pgmpy,sandeepkrjha/pgmpy,jhonatanoliveira/pgmpy,pgmpy/pgmpy,khalibartan/pgmpy,sandeepkrjha/pgmpy,ankurankan/pgmpy,kris-singh/pgmpy,kris-singh/pgmpy,abinashpanda/pgmpy,ankurankan/pgmpy