Create automated tests

[tasket]

A good testing regime could include the following:

• Perform an initial backup
• Verify volume
• Perform an incremental backup
• Verify volume
• Prune first backup
• Verify volume
• Diff volume (cross-check with source vol data)

---

Changing program_name in the code could allow the test data set to be created under a different base folder name without interfering with real-life backup data.

[DemiMarie]

Other areas I recommend testing:

1. Deliberately tamper with the archive, and check that the tampering is detected on restore.
2. Attempt to roll back the archive to an earlier version, and test that this is detected.