more compatibility checks with input types of numpy

auto_ml/utils.py

@@ -204,7 +204,7 @@ def transform(self, in_vals):
         return_vals = []
         for val in in_vals:
             if not isinstance(val, str):
-                if isinstance(val, float) or isinstance(val, int) or val is None:
+                if isinstance(val, float) or isinstance(val, int) or val is None or isinstance(val, np.generic):
                     val = str(val)
                 else:
                     val = val.encode('utf-8').decode('utf-8')