Pull images when building the box
Pull images when building the box

Squashed commit of the following:

commit eaf486bd0927fd77c206be7dae23f9f7dca25607
Merge: 15d515e fb4e258
Author: Greg Linton <4f6f52e328b656e196ac7d4e6beb69854429601c@pagodabox.com>
Date:   Mon Jul 13 14:15:48 2015 -0400

    Merge branch 'master' into feature/preload-images

commit 15d515ed7fcc217e7455fe558ff0e9c81812fad5
Merge: 364eeb2 e168beb
Author: Braxton Huggins <d958d069c839e7864d6941839466f4aec3b11963@pagodabox.com>
Date:   Thu Jun 25 09:10:41 2015 -0600

    Merge branch 'master' into feature/preload-images

commit 364eeb292b4d0276b63a7c6629ebb5d222e69f4d
Author: Braxton Huggins <d958d069c839e7864d6941839466f4aec3b11963@pagodabox.com>
Date:   Thu Jun 25 09:09:05 2015 -0600

    pull images when buiding box

Author: Braxton <d958d069c839e7864d6941839466f4aec3b11963@pagodabox.com>
Reviewer: Greg <4f6f52e328b656e196ac7d4e6beb69854429601c@pagodabox.com>

pagodabox/nanobox-boot2docker,pagodabox/nanobox-boot2docker