LIBCLOUD-858: Fix Listing Libvirt Nodes with Python 3

[femnad]

Fix Listing Libvirt Nodes with Python 3

Description

Listing nodes with the Libvirt provider fails on Python 3 because of a split operation on a bytes object where the delimiter is not a bytes object.

Use the ensure_string function from the py3 module to ensure that the output of a subprocess.Popen call is always a string for Python 2 and 3. Also add a test to convert the mock command output results to bytes objects if the active Python version is 3.

Status

• done, ready for review

Checklist (tick everything that applies)

• Code linting (required, can be done after the PR checks)
• Documentation
• Tests
• ICLA (required for bigger changes)

[tonybaloney]

great, thanks for also contributing the test to assert the issue exists and the change resolves it. 👍