Back-fill tests for MigrateDisk

It looks integration-ish to guard against a subsequent refactoring.

Signed-off-by: Ian Lesperance <ilesperance@pivotallabs.com>
Even more conservative test for MigrateDisk

Signed-off-by: Tony Hansmann <thansmann@pivotallabs.com>
Rename Linux::Disk to Linux::DiskManager
rename the files and require
Extract disk mounting and directory copying logic

A message handler should not have the knowledge of how to mount a disk

Signed-off-by: Tony Hansmann <thansmann@pivotallabs.com>
Add bosh_cli dependency for Bosh::Dev

[finishes #57199558]

Signed-off-by: Rob Day-Reynolds <rdayreynolds@pivotallabs.com>