removable_storage_test fails with trace

[Daniel Manrique]

This is a consequence of the new xhci code to detect usb3 devices.

How to reproduce:

- Insert a memory card
- /usr/lib/2013.com.canonical.certification:checkbox/bin/removable_storage_test -s 10 --memorycard sdio usb scsi

Actual result:

Traceback (most recent call last):
  File "./removable_storage_test", line 30, in <module>
    from checkbox_support.udev import get_udev_xhci_devices
ImportError: cannot import name 'get_udev_xhci_devices'

Marking as critical because 1) it should be a small fix, and 2) it's causing ALL removable storage tests on a certification run to fail.

[Daniel Manrique (roadmr)]

This happened because python3-checkbox-support is at 0.2-1 with Ubuntu, since we don't request a specific version when installing canonical-certification-client, the current one satisfies the requirement, but the version with the required code for this is 0.3~dev-something. We probably should update dependencies of plainbox-provider-checkbox (where the script lives) to require a version of python3-checkbox-support that doesn't cause it to break.

For now the workaround is to manually install python3-checkbox-support.

BTW, python3-plainbox-support is apparently the only package that didn't upgrade to the newer-than-ubuntu version when installing c-c-client.