Support automaticly infer world rank

[fedml-zijianhu]

Automatic rank inference will be used to support the following functions

FedML/python/fedml/core/alg_frame/server_aggregator.py

Lines 28 to 29 in 2f842a5

	def is_main_process(self):
	return True

FedML/python/fedml/core/alg_frame/client_trainer.py

Lines 28 to 29 in 2f842a5

	def is_main_process(self):
	return True

[fedml-dimitris]

@fedml-zijianhu What is the status of this?

[Deleted user]

It's planned but have low priority