Made the test for a testdb done-ish

Description: Now tests for getting specific document, deleting specific
document, saving document, retrieving multiple documents are done.
Ready for the documentMapper to be implemented.
Important: Hence, that the location of the mapperclass and its
method-names may not be the same later on. This test is just to show
its functionality should be used.
Warning: Remember, that the db gets two documents (“Article 1”,
“Article 2) before the test runs, and in the test it gets a “Article 3”
and deletes the “Article 1”. Then “Article 2” and “Article 3” gets
deleted after the tests.
Commit: Christopher