Fix failing tests about arc2

[cbinding]

Hi Konrad, thanks for following up - looking at one example https://github.com/semsol/arc2/blob/master/tests/db_adapter_depended/store/ARC2_StoreTest.php test 'testMultipleInsertQuerysInDifferentGraphs' which is currently failing - the assertion in the test itself appears to be incorrect. It inserts 1 triple into graph1 and 2 triples into graph2 but then asserts there should now be 1 triple in each graph - this test will always fail.

[cbinding]

Looking at the next failing test https://github.com/semsol/arc2/blob/master/tests/db_adapter_depended/store/query/LoadQueryTest.php 'testLoad' - it is trying to load a file which is not present at the location given - the path https://raw.githubusercontent.com/semsol/arc2/master/tests/sparql11/w3c-tests/move/manifest.ttl returns 404 not found - so again this test will always fail as it cannot load this data. I think the 'correct' path should be https://raw.githubusercontent.com/semsol/arc2/master/tests/data/turtle/manifest.ttl
The tests are incorrect, that is why they are failing.

[cbinding]

The 3rd (out of 3) failing test is just a variation on the 2nd, as it is attempting to load the same incorrect test data file path

[k00ni]

Further discussion in related PR #126.