load human-human, human-viral and viral-viral PPI data from IntActFTP

use interSpeciesInteractome and fullInteractome to retrieve and load human-human, human-viral and viral-viral PPI data from IntActFTP

to be used with humanViralDegree

loadHumanViralPPI(directory = "./data_files/",
  loadIntActFTP_dir = "./data_files/IntActRelease_2017Nov13/",
  release = "2017Nov13")

Arguments

directory	to find / keep PPI data (arg for fullInteractome, interSpeciesInteractome))
loadIntActFTP_dir	where to find specific release (arg for loadIntActFTP)
release	release date