bug fix: Properly generate guest disks on VMTemplate

Commits cdd146a9 and 749abbf8 changed the way VMTemplate generates the
guest disks XML but, due a merge issue, they did not update the
to_vm_xml() function that was pointing to non-existing functions:
_get_iscsi_disks_xml() and _get_scsi_disks_xml()

Signed-off-by: Aline Manera <alinefm@linux.vnet.ibm.com>
Update FeatureTests to use the same libvirt connection used by Model

The former code was running the FeatureTests with the system libvirt
connection, so if a developer used Model() with a different
libvirt URI the feature tests would report a false positive result.
To avoid this problem share the libvirt connection used by Model() with
FeatureTests.

Signed-off-by: Aline Manera <alinefm@linux.vnet.ibm.com>
Set domain type in FeatureTests according libvirt URI

When using the libvirt URI 'test:///default' the domain type must be
'test' instead of 'kvm'

Signed-off-by: Aline Manera <alinefm@linux.vnet.ibm.com>
Move featuretests.py to /model

FeatureTests is only used by Model() as it tests the libvirt and qemu
capabilities. So move it to /model

Signed-off-by: Aline Manera <alinefm@linux.vnet.ibm.com>
MockModel refactor

Signed-off-by: Aline Manera <alinefm@linux.vnet.ibm.com>
Update test_authorization.py to use the new MockModel

Signed-off-by: Aline Manera <alinefm@linux.vnet.ibm.com>
fix