Fix test

Author: mpv1989

src/test/java/com/arangodb/ArangoGraphTest.java

@@ -115,7 +115,7 @@ public void create() {
 assertThat(result, is(notNullValue()));
 assertThat(result.getName(), is(GRAPH_NAME + "_1"));
 } finally {
-db.graph(GRAPH_NAME).drop();
+db.graph(GRAPH_NAME + "_1").drop();
 }
 }