review token management logic in OpenShifts class

[simkam]

There is OpenShifts.getToken method that returns either configured token xtf.openshift.admin/master.token or tries to load token from cluster using username and password.

On other hand there are methods that always use only configured token:

public static String getMasterToken() {
        return getToken(OpenShiftConfig.masterToken(), OpenShiftConfig.masterUsername(), OpenShiftConfig.masterPassword(),
                OpenShiftConfig.masterKubeconfig());
}