Description: Mark additional tests as requiring network.
Author: Bas Couwenberg <sebastic@debian.org>
Forwarded: https://github.com/SciTools/cartopy/issues/1206

--- a/lib/cartopy/tests/mpl/test_nightshade.py
+++ b/lib/cartopy/tests/mpl/test_nightshade.py
@@ -27,6 +27,7 @@ from cartopy.feature.nightshade import N
 from cartopy.tests.mpl import ImageTesting
 
 
+@pytest.mark.network
 @ImageTesting(['nightshade_platecarree'])
 def test_nightshade_image():
     # Test the actual creation of the image