Set parameters for v0.5.4

[YungSang]

Revise the iso file path and checksum for boot2docker v0.5.4

[ernoaapa]

I tested this and the building fails. The provisioning script execution fails because there is no /var/lib/docker/vm/ssh/ dir anymore.

Also there is another persisting problem with 0.5.4 boot2docker described here #17. If you don't have that problem, please let us know.

[YungSang]

@eaapa
This PR doesn't work solo to build a box.
You need #14 and #15 with this PR.
I demonstrate it here.
https://github.com/YungSang/boot2docker-vagrant-box/releases

It's almost same as the revised version of #17, but follows the original manner as possible.

[YungSang]

@eaapa I believe the problem you described at #17 is that boot2docker.iso 0.5.x can not mount the vmdk in the original boot2docker-vagrant-box.
Because of this, the files can't be copied to the persistent disk and @drewcrawford formats the vmdk on provision in his revised version to mount it properly.

[ernoaapa]

You right @YungSang, sorry my mistake.
Your tag v0.5.4 works and thank for sharing the prebuilt boot2docker.box, so I can use that :) Cheers!

[YungSang]

@eaapa You're welcome. 😃

[mitchellh]

Fixed with #18 :)