Proxied Cluster Support

[gabemontero]

today openshift build v1 can obtain certs for the global proxy and ensure they are available to the build process

ultimately buildv2 should have some form of this

it very well might make sense for DEVEX to help abstact out logic used for build v1 for use by buildv2 .... https://github.com/gabemontero/obu is a prototype of such an endeavor