message: [bugfix] numeric value for date fields in table viz
  Bug was present only when using the NOT GROUPED BY option
  fixes
diff: @@ -353,6 +353,12 @@ class TableViz(BaseViz):
  columns=list(df.columns),
  )
  + def json_dumps(self, obj):
  + if self.form_data.get('all_columns'):
  + return json.dumps(obj, default=utils.json_iso_dttm_ser)
  + else:
  + return super(TableViz, self).json_dumps(obj)
  +
  class PivotTableViz(BaseViz):
  