Found when using older oc clients after removing v1beta3 from master

Clients 1.0.4 and earlier are defaulting to v1beta3

$ oc get projects --token=... --server=https://localhost:8443 --loglevel=8
I1020 13:42:02.326013   27447 debugging.go:98] GET https://localhost:8443/osapi/v1beta3/projects
I1020 13:42:02.326065   27447 debugging.go:105] Request Headers:
I1020 13:42:02.326073   27447 debugging.go:108]     User-Agent: oc/v1.0.4 (linux/amd64) openshift/757efd9

Working versions: 1.0.5+
Broken versions: 1.0.4 and below

Passing --api-version=v1 allows these clients to talk to a v1 server.

We should:

1. Document how to make older clients work with v1
2. Ensure current code is doing negotiate, not hard-coding v1

cc @mfojtik