updated README to include celery tasks and roles
updated README to include celery tasks and roles

pkoro/okeanos-LoD,stevelaskaridis/okeanos-LoD,stevelaskaridis/okeanos-LoD,pkoro/okeanos-LoD,stevelaskaridis/okeanos-LoD,pkoro/okeanos-LoD,themiszamani/okeanos-LoD,pkoro/okeanos-LoD,grnet/okeanos-LoD,themiszamani/okeanos-LoD,themiszamani/okeanos-LoD,themiszamani/okeanos-LoD,stevelaskaridis/okeanos-LoD,grnet/okeanos-LoD,grnet/okeanos-LoD,grnet/okeanos-LoD