While following the instructions here I got the following error:
$ sudo make bash
[...]
Step 1/16 : FROM quay.io/3scale/docker:ci-2.3.1-3
ERROR: Service 'cache' failed to build: unauthorized: access to the requested resource is not authorized
I tried accessing https://quay.io/3scale/docker:ci-2.3.1-3 and after logging in with my RH account I get a 403 Forbidden page.