Remove futures from requirements

Remove futures from requirements because this library
not used in Ironic (needed for abandoned 63904).

Change-Id: I9cb121f6ba878a9ff0639cfeb10c9b1f32d8718a
Rewrite images tests with mock

test_images module was using fixtures to test ironic.common.images
module. Mock is now used instead. New tests added. fetch_to_raw is
not tested as it is going to be removed as mentioned here:
https://review.openstack.org/#/c/115974/

Change-Id: Id931b6d9cc1213f1347a9324510580e14c601412
Closes-bug: #1361672
Merge "Rewrite images tests with mock"
Merge "Remove futures from requirements"
IloVirtualMediaIscsi deploy driver

This commit introduces a new deploy driver which uses iLO virtual
media to boot up proliant baremetal nodes, and uses iSCSI to deploy
the baremetal nodes.

Change-Id: I98f47ed6082a3a28fce3148f6d5177cdb5c61881
Implements: blueprint ironic-ilo-virtualmedia-driver