changed default values for beta_vector and evidence
changed default values for beta_vector and evidence

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