Create system test for tar files

**Goal**

A set of system tests exist that perform tar diff operations using the cli tools on a set of test tar files and verify the results.

**Acceptance Criteria**

A list of verification conditions, successful functional tests, or expected outcomes in order to declare this story/task successfully completed.

- Verify a code coverage level of ~ 80% is maintained
- Verify a tar diff test runs on a set of checked in tar files, and confirms the combined file (old file plus diff file) matches the new file