ngCloak is removed by angular when parsing the template, however this
doesn't seem to be enough to keep the content hidden until the
application is completely ready.
We accomplish this by setting `display: none` to the `body` element and
maing it display again when our main controller starts, at which point
we know everything is up and running.
This screen informs the user that the burn has completed and that the
drive can be ejected directly.
It also provides a button to burn another image without exitting the
application.
Fixes: https://github.com/resin-io/herostratus/issues/41
Currently we only pass the drive device. By passing all the object
(containing the mountpoint, size, etc) we allow more control to the
writer in how to treat the device before/during/after the burning
process.
