Replace 'isAlive()' with 'is_alive()' for Python 3.9 compatibility
Replace 'isAlive()' with 'is_alive()' for Python 3.9 compatibility

KennethNielsen/SoCo,petteraas/SoCo,SoCo/SoCo,petteraas/SoCo,SoCo/SoCo,petteraas/SoCo,KennethNielsen/SoCo