Update news images
Update news images

use github image urls, since the old ones no longer work now that frontend is
generating the markdown

cBioPortal/cbioportal,angelicaochoa/cbioportal,pughlab/cbioportal,cBioPortal/cbioportal,sheridancbio/cbioportal,mandawilson/cbioportal,d3b-center/pedcbioportal,onursumer/cbioportal,d3b-center/pedcbioportal,onursumer/cbioportal,pughlab/cbioportal,onursumer/cbioportal,mandawilson/cbioportal,d3b-center/pedcbioportal,zhx828/cbioportal,angelicaochoa/cbioportal,cBioPortal/cbioportal,zhx828/cbioportal,n1zea144/cbioportal,zhx828/cbioportal,angelicaochoa/cbioportal,onursumer/cbioportal,mandawilson/cbioportal,pughlab/cbioportal,pughlab/cbioportal,angelicaochoa/cbioportal,pughlab/cbioportal,angelicaochoa/cbioportal,zhx828/cbioportal,pughlab/cbioportal,cBioPortal/cbioportal,sheridancbio/cbioportal,d3b-center/pedcbioportal,sheridancbio/cbioportal,zhx828/cbioportal,mandawilson/cbioportal,n1zea144/cbioportal,sheridancbio/cbioportal,angelicaochoa/cbioportal,mandawilson/cbioportal,n1zea144/cbioportal,onursumer/cbioportal,d3b-center/pedcbioportal,d3b-center/pedcbioportal,n1zea144/cbioportal,n1zea144/cbioportal,mandawilson/cbioportal,mandawilson/cbioportal,n1zea144/cbioportal,onursumer/cbioportal,d3b-center/pedcbioportal,cBioPortal/cbioportal,n1zea144/cbioportal,sheridancbio/cbioportal,zhx828/cbioportal,zhx828/cbioportal,angelicaochoa/cbioportal,sheridancbio/cbioportal,pughlab/cbioportal,cBioPortal/cbioportal