Add David Shrewsbury to HP

Change-Id: I2fc427fb56d5332d21fdb99ec8ac7c9a6a3878c4
Reviewed-on: https://review.openstack.org/31202
Approved: Monty Taylor <mordred@inaugust.com>
Reviewed-by: Monty Taylor <mordred@inaugust.com>
Tested-by: Jenkins