Description of problem:
When assign the dedicated admin role to group met error: Adding cluster role dedicated-cluster-admin to groups 'test' failed: Error from server (NotFound): the server could not find the requested resource

Version-Release number of selected component (if applicable):
openshift v3.7.0-0.127.0
kubernetes v1.7.0+80709908fd
etcd 3.2.1

How reproducible:
always

Steps to Reproduce:
1. Run the python scrip to assign the dedicated admin role to groups;
`python apply-dedicated-roles.py  -p dedicated-project-admin.json -c dedicated-cluster-admin.json -d dedicated-admin-group.json -g test -v`

Actual results:
1. Met error: 
Arguments to program:
    ProjectRole = dedicated-project-admin
    ClusterRole = dedicated-cluster-admin
    Groups = ['test']
    SkipProjects = ['default', 'openshift-infra']
    ReCreate = False
    Verbose = True

Checking OpenShift CLI command ... 
OK
Checking OpenShift admin CLI command ... 
OK
Getting cluster role dedicated-cluster-admin if exists ... 
OK
Creating cluster role dedicated-cluster-admin ... 
OK
Getting dedicated admin group dedicated-admins to check if it exists ... 
OK
Creating dedicated admin group dedicated-admins ... 
OK
Adding cluster role dedicated-cluster-admin to groups 'test' ... 
FAIL
Error: Adding cluster role dedicated-cluster-admin to groups 'test' failed: Error from server (NotFound): the server could not find the requested resource

Expected results:
1. Should assign the dedicated admin role succeed.

Additional info: