Add testing for Delta.newDeltaFromGitHistory()

[hkong-mitre]

Delta.newDeltaFromGitHistory() is one of the most important functions in Delta.ts, but is difficult to test. Need to figure out a way to consistently test it. The following is code that was originally in Delta.test.ts. A better test should be implemented.

  // it(`newDeltaFromGitHistory() properly builds a Delta object from git history`, async () => {
  //   const delta = await Delta.newDeltaFromGitHistory("2023-02-16T00:00:00.000Z", "2023-03-21T23:59:59.999Z", process.env.CVES_TEST_BASE_DIRECTORY);
  //   console.log(`delta:  ${JSON.stringify(delta, null, 2)}`);
  //   expect(delta.numberOfChanges).toBe(3);
  //   expect(delta.unknown.length).toBe(3);
  //   expect(delta.unknown[0].cveId).toBe(`CVE-1970-0001`);
  // });