Cloud storage: first test case for a very simple merge

- We add a dive while offline.
- On a different computer (here simulated by a different local cache) we
  add a different file.
- Now we go back to the previous local cache (the one where we added a
  different dive in the first step) and take that online (i.e., connect to
  cloud storage). Now both of the new dives should have been added to our
  data file.

This is a rather trivial test with no conflict and a straight forward
merge. We need to add a lot more test cases to make sure this works as
expected and doesn't leave the user with a corrupt state.

Ideally whatever happens, the user should never see an error...

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

tests/testgitstorage.h

@@ -10,6 +10,7 @@ private slots:
 	void testGitStorageLocal();
 	void testGitStorageCloud();
 	void testGitStorageCloudOfflineSync();
+	void testGitStorageCloudMerge();
 };
 
 #endif // TESTGITSTORAGE_H