Add np.bool in json encoder

Author: giadarol

xobjects/hybrid_class.py

@@ -88,6 +88,8 @@ def default(self, obj):
             return obj.tolist()
         elif np.issubdtype(type(obj), np.integer):
             return int(obj)
+        elif isinstance(obj, np.bool):
+            return bool(obj)
         else:
             return json.JSONEncoder.default(self, obj)