Handles flake8.

Author: ramaroesilva

pvlib/pvsystem.py

@@ -437,7 +437,7 @@ def get_cell_temperature(self, poa_global, temp_air, wind_speed, model,
         effective_irradiance : numeric or tuple of numeric, optional
             The irradiance that is converted to photocurrent in W/m^2.
             Only used for some models.
-   
+
         ir_down: numeric, optional
             Downwelling infrared radiation from the sky, measured on a
             horizontal surface in W/m^2. Only used in ``'faiman_rad'`` model.