Ignore rubocop offense in CentOS stemcell spec.
Ignore rubocop offense in CentOS stemcell spec.

Signed-off-by: Mike Stallard <ce9d93963c1e9acfe234dadf883570c71fd6758d@pivotallabs.com>

barthy1/bosh,barthy1/bosh,barthy1/bosh,barthy1/bosh