Address flake8 requirement

Author: smartlixx

lib/cartopy/mpl/geoaxes.py

@@ -1005,11 +1005,12 @@ def stock_img(self, name='ne_shaded'):
         """
         Add a standard image to the map.
 
-        Currently, there are 2 options. 
-        1: 'ne_shaded'(default) a downsampled version of the Natural Earth shaded relief raster.
-        2: 'etopo1' a downsampled version of global relief model of Earth's surface that
-        integrates land topography and ocean bathymetry. This option is the same as the etopo1 
-        from Basemap.
+        Currently, there are 2 options:
+        1. 'ne_shaded'(default) a downsampled version of the Natural Earth
+           shaded relief raster.
+        2. 'etopo1' a downsampled version of global relief model of Earth's
+           surface that integrates land topography and ocean bathymetry. This
+           option is the same as the etopo1 from Basemap.
         """
         if name == 'ne_shaded':
             import os