Another flake8 issue handled.

Author: ramaroesilva

tests/test_pvsystem.py

@@ -518,7 +518,7 @@ def test_PVSystem_faiman_rad_celltemp(mocker):
 def test_PVSystem_ross_celltemp(mocker):
     # example value (could use equivalent noct as alternative input)
     k = 0.0208  # free-standing system
-  
+
     temp_model_params = {'k': k}
     system = pvsystem.PVSystem(temperature_model_parameters=temp_model_params)
     mocker.spy(temperature, 'ross')