Fixed subtle property accessor bug in Gcisbase class stemming from excessive...

Fixed subtle property accessor bug in Gcisbase class stemming from excessive cleverness creating attributes and properties on subclasses.
Added assertions to test suite

src/domain.py

@@ -47,7 +47,7 @@ class Gcisbase(object):
 
     def as_json(self, indent=0, omit_fields=[]):
         out_fields = set(self.gcis_fields) - (set(['uri', 'href']) | set(omit_fields))
-        return json.dumps({f: self.__dict__[f] for f in out_fields}, indent=indent)
+        return json.dumps({f: getattr(self, f) for f in out_fields}, indent=indent)
 
 
 class Figure(Gcisbase):

src/test_suite.py

@@ -84,6 +84,11 @@ def test_dataset_special_properties():
     ds.publication_year = 'TBD'
     assert ds.publication_year is None
 
+    assert ds.access_dt == '2011-12-31T00:00:00'
+
+    #This one was subtle. Make sure as_json() still works with properties.
+    ds_json_out = json.loads(ds.as_json())
+    assert ds_json_out['access_dt'] == '2011-12-31T00:00:00'
 
 
 if __name__ == '__main__':