Move to boot2docker 1.0.0 with VB guest additions

Use the boot2docker iso generated using info from this gist:
https://gist.github.com/mattes/2d0ffd027cb16571895c. More about it
in this blog entry:
https://medium.com/boot2docker-lightweight-linux-for-docker/boot2docker-together-with-virtualbox-guest-additions-da1e3ab2465c