grid_*_cpu not working on MAC/OSX

[tkornuta-ibm]

Describe the bug Running grid_trainer_cpu on MAC results in:

max_processes = min(len(os.sched_getaffinity(0)), self.max_concurrent_runs) AttributeError: module 'os' has no attribute 'sched_getaffinity'

It seems that OSX doesn't support this :] https://stackoverflow.com/questions/42538153/python-3-6-0-os-module-does-not-have-sched-getaffinity-method Desktop (please complete the following information):

• OS: OSX
• OS version: Darwin-18.0.0-x86_64-i386-64bit

[tkornuta-ibm]

https://stackoverflow.com/questions/1006289/how-to-find-out-the-number-of-cpus-using-python

[tkornuta-ibm]

grid_tester_cpu and grid_analyser are also not working :]