Added the hierarchical roles design doc to the list of design docs.
Added the hierarchical roles design doc to the list of design docs.

gsantovena/mesos,jpeach/mesos,craimbert/mesos,andschwa/mesos,reneploetz/mesos,verizonlabs/mesos,verizonlabs/mesos,jpeach/mesos,andschwa/mesos,zmalik/mesos,neilconway/mesos,verizonlabs/mesos,dforsyth/mesos,zmalik/mesos,asamerh4/mesos,asamerh4/mesos,chhsia0/mesos,neilconway/mesos,reneploetz/mesos,chhsia0/mesos,kaysoky/mesos,kaysoky/mesos,reneploetz/mesos,kaysoky/mesos,dforsyth/mesos,verizonlabs/mesos,Gilbert88/mesos,chhsia0/mesos,jpeach/mesos,chhsia0/mesos,abudnik/mesos,chhsia0/mesos,abudnik/mesos,asamerh4/mesos,zmalik/mesos,gsantovena/mesos,Gilbert88/mesos,dforsyth/mesos,reneploetz/mesos,andschwa/mesos,jpeach/mesos,verizonlabs/mesos,reneploetz/mesos,kaysoky/mesos,kaysoky/mesos,Gilbert88/mesos,jpeach/mesos,abudnik/mesos,chhsia0/mesos,abudnik/mesos,craimbert/mesos,craimbert/mesos,asamerh4/mesos,reneploetz/mesos,neilconway/mesos,gsantovena/mesos,jpeach/mesos,zmalik/mesos,asamerh4/mesos,neilconway/mesos,gsantovena/mesos,Gilbert88/mesos,zmalik/mesos,jpeach/mesos,craimbert/mesos,abudnik/mesos,dforsyth/mesos,andschwa/mesos,dforsyth/mesos,verizonlabs/mesos,kaysoky/mesos,andschwa/mesos,dforsyth/mesos,craimbert/mesos,dforsyth/mesos,abudnik/mesos,gsantovena/mesos,reneploetz/mesos,asamerh4/mesos,Gilbert88/mesos,andschwa/mesos,gsantovena/mesos,asamerh4/mesos,neilconway/mesos,craimbert/mesos,neilconway/mesos,andschwa/mesos,neilconway/mesos,kaysoky/mesos,Gilbert88/mesos,zmalik/mesos,craimbert/mesos,abudnik/mesos,gsantovena/mesos,chhsia0/mesos,zmalik/mesos,verizonlabs/mesos,Gilbert88/mesos