Rename type.py to volume_type.py
Rename type.py to volume_type.py

For Volume V1, we have a type.py file which should be renamed to
volume_type.py (as it's named for V2).

Change-Id: If860bbafe4a801d8b4fa06938eef20658c4fcc2c
Closes-Bug: 1475958

dtroyer/osc-lib