Fix up ruby packaging script
Fix up ruby packaging script

[#89665398](https://www.pivotaltracker.com/story/show/89665398)

Signed-off-by: Xuebin He <a24423da5583aa8407f2dcc30b6a21a9dc802b67@emc.com>

wcamarao/bosh-vsphere-cpi-release,cloudfoundry-incubator/bosh-vsphere-cpi-release,cloudfoundry-incubator/bosh-vsphere-cpi-release,nimbus-cloud/bosh-vsphere-cpi-release,wcamarao/bosh-vsphere-cpi-release,cloudfoundry-incubator/bosh-vsphere-cpi-release,cloudfoundry-incubator/bosh-vsphere-cpi-release,nimbus-cloud/bosh-vsphere-cpi-release,wcamarao/bosh-vsphere-cpi-release,cloudfoundry-incubator/bosh-vsphere-cpi-release,nimbus-cloud/bosh-vsphere-cpi-release