modified __init__.py to import all the Exceptions directly
modified __init__.py to import all the Exceptions directly

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