pep8 cleanup

openmdao/components/add_subtract_comp.py

@@ -159,7 +159,7 @@ def add_equation(self, output_name, input_names, vec_size=1, length=1, val=1.0,
             Scaling parameter. The value in the user-defined res_units of this output's residual
             when the scaled value is 1. Default is 1.
         tags : str or list of strs
-            User defined tags that can be used to filter what gets listed when calling 
+            User defined tags that can be used to filter what gets listed when calling
             list_inputs and list_outputs and also when listing results from case recorders.
         """
         kwargs = {'units': units, 'res_units': res_units, 'desc': desc,