added method stub (#28)
added tests for new delete() method (#28)
added concrete remove() method to simplify mocking (#28)
implemented delete() (#28)
added test (edge case, insertion via SPARQL update) (#28)
improved test (checks if literal can be selected as expected) (#28)
marked test as skipped as long as no workaround is available (#28)
refactoring: extracted base test case (#28)
fixed documented type (#28)
moved test to base class (#28)
configured Stardog to use the NQuads batch processor (does not mix up types in edge cases) (#28)
introduced workaround for deleting triples that meet an edge case condition (#28)