Use parted (If available) to partition disk, else fallback to sfdisk.
Use parted (If available) to partition disk, else fallback to sfdisk.

Signed-off-by: Shishir Mahajan <shishir.mahajan@redhat.com>

Closes: #191
Approved by: rhvgoyal

thescriptbender/container-storage-setup,shishir-a412ed/docker-storage-setup