disk/api.py needs tests

[Sahid Orentino]

There are missing tests to cover correctly every methods defined in disk/api.py

- mkfs
- resize2fs
- get_disk_size
- extend
- can_resize_image
- is_image_partitionless
- DiskImage
- inject_data
- ....

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: master
Review: https://review.openstack.org/67430

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/67430
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=e19d9653604a80839534abf7462a4fa8b4d146fa
Submitter: Jenkins
Branch: master

commit e19d9653604a80839534abf7462a4fa8b4d146fa
Author: Sahid Orentino Ferdjaoui <email address hidden>
Date: Fri Jan 17 12:12:25 2014 +0100

    disk/api.py: refactors extends and adds missing tests

    The method extend does not log any information if there is a
    problem during the resize with "resize2fs".

    This patch refactor extend and adds missing tests.

    Change-Id: I81079a79e0449381440f202f6143b48f96453a11
    Related-Bug: #1270086