add parallel blob download to deploy script
add parallel blob download to deploy script

Signed-off-by: Kara Felix <9b369653f4c3fdaae4fab8370dcf65ae870bb3b6@us.ibm.com>

cloudfoundry-incubator/diego-release,cloudfoundry-incubator/diego-release,cloudfoundry-incubator/diego-release,cloudfoundry-incubator/diego-release