Fix Vagrantfile provisioning to be idempotent
Fix Vagrantfile provisioning to be idempotent

[#111105094]

Signed-off-by: Ben Moss <80bec717c12290923c80384e0a5fc28cdf75a97e@pivotal.io>

mattcui/bosh-agent,gu-bin/bosh-agent,gu-bin/bosh-agent,mattcui/bosh-agent,gu-bin/bosh-agent,cloudfoundry/bosh-agent,mattcui/bosh-agent,cloudfoundry/bosh-agent