Backport the new dependency test.

Author: Julian

tests/draft3/dependencies.json

@@ -98,6 +98,11 @@
                 "data": {"foo": 1, "bar": 2},
                 "valid": true
             },
+            {
+                "description": "no dependency",
+                "data": {"foo": "quux"},
+                "valid": true
+            },
             {
                 "description": "wrong type",
                 "data": {"foo": "quux", "bar": 2},