Add DiskPartitioner

DiskPartitioner is a convenient wrapper around the parted tool, this
wrapper will make things easier for fixing other problems in Ironic like
removing the swap partition if not specified, having a more consistent
partition layout or future work like creating GPT (GUID Partition Table)
partitions (needed for creating partitions with size bigger than 2TB),
efi partitions, etc..

Change-Id: I44be217d1e55778ed94f27603ce0537ff740febf
Partial-Bug: #1297925
Partial-Bug: #1298362
Merge "Add DiskPartitioner"