Run PEPATAC on a PEP on PEPHUB

[donaldcampbelljr]

Recently attempted to run PEPATAC from a pep on pephub. However, the project-level pipeline, pepatac collator, calls:

pepatac/pipelines/pepatac_collator.py

Lines 79 to 81 in 924aefa

	project = peppy.Project(args.config_file)
	#results_subdir = "/home/jps3dp/processed/pepatac_tutorial//processed/results_pipeline"

This expects a config file with a .yaml file but for a PEP on PEPHub it must also be able to load a PEP from a registry path.

This discussion has come up here:
pepkit/peppy#462