Remove unused Backend type-hint variable and empty sampling_utils.py

Author: ricardoV94

pymc/__init__.py

@@ -69,7 +69,6 @@ def __set_compiler_flags():
 from pymc.printing import *
 from pymc.sampling import *
 from pymc.sampling_forward import *
-from pymc.sampling_utils import *
 from pymc.smc import *
 from pymc.stats import *
 from pymc.step_methods import *

pymc/sampling_utils.py

@@ -53,7 +53,6 @@
 pymc/plots/__init__.py
 pymc/sampling.py
 pymc/sampling_forward.py
-pymc/sampling_utils.py
 pymc/smc/__init__.py
 pymc/smc/sampling.py
 pymc/smc/kernels.py