Change README.md to point to okeanos.grnet.gr/platforms
Change README.md to point to okeanos.grnet.gr/platforms

ibyron/e-science,grnet/e-science,ioannisstenos/e-science,ibyron/e-science,ioannisstenos/e-science,grnet/e-science,grnet/e-science,ibyron/e-science,grnet/e-science,ioannisstenos/e-science,ioannisstenos/e-science,ibyron/e-science,grnet/e-science,ioannisstenos/e-science,ibyron/e-science