Description: Mark tests requiring network accordingly.
 Network is not available in the Debian package build environment.
Author: Bas Couwenberg <sebastic@debian.org>

--- a/lib/cartopy/tests/mpl/test_feature_artist.py
+++ b/lib/cartopy/tests/mpl/test_feature_artist.py
@@ -61,6 +61,7 @@ def cached_paths(geom, target_projection
     return geom_cache.get(target_projection, None)
 
 
+@pytest.mark.natural_earth
 @pytest.mark.mpl_image_compare(filename='feature_artist.png')
 def test_feature_artist_draw(feature):
     fig, ax = robinson_map()
@@ -69,6 +70,7 @@ def test_feature_artist_draw(feature):
     return fig
 
 
+@pytest.mark.natural_earth
 @pytest.mark.mpl_image_compare(filename='feature_artist.png')
 def test_feature_artist_draw_facecolor_list(feature):
     fig, ax = robinson_map()
@@ -77,6 +79,7 @@ def test_feature_artist_draw_facecolor_l
     return fig
 
 
+@pytest.mark.natural_earth
 @pytest.mark.mpl_image_compare(filename='feature_artist.png')
 def test_feature_artist_draw_cmap(feature):
     fig, ax = robinson_map()
@@ -87,6 +90,7 @@ def test_feature_artist_draw_cmap(featur
     return fig
 
 
+@pytest.mark.natural_earth
 @pytest.mark.mpl_image_compare(filename='feature_artist.png')
 def test_feature_artist_draw_styled_feature(feature):
     geoms = list(feature.geometries())
@@ -98,6 +102,7 @@ def test_feature_artist_draw_styled_feat
     return fig
 
 
+@pytest.mark.natural_earth
 @pytest.mark.mpl_image_compare(filename='feature_artist.png')
 def test_feature_artist_draw_styler(feature):
     geoms = list(feature.geometries())
--- a/lib/cartopy/tests/mpl/test_features.py
+++ b/lib/cartopy/tests/mpl/test_features.py
@@ -49,6 +49,7 @@ def test_natural_earth_custom():
 
 @pytest.mark.xfail('i386' in sysconfig.get_config_var('MULTIARCH'),
                    reason='Limitations of i386 architecture')
+@pytest.mark.network
 @pytest.mark.skipif(not _HAS_PYKDTREE_OR_SCIPY, reason='pykdtree or scipy is required')
 @pytest.mark.mpl_image_compare(filename='gshhs_coastlines.png', tolerance=0.95)
 def test_gshhs():
--- a/lib/cartopy/tests/mpl/test_gridliner.py
+++ b/lib/cartopy/tests/mpl/test_gridliner.py
@@ -262,6 +262,7 @@ def test_grid_labels_tight():
     return fig
 
 
+@pytest.mark.natural_earth
 @pytest.mark.mpl_image_compare(
     filename='gridliner_constrained_adjust_datalim.png',
     tolerance=grid_label_tol)
@@ -496,6 +497,7 @@ def test_gridliner_count_draws():
         mocked.assert_called_once()
 
 
+@pytest.mark.natural_earth
 @pytest.mark.mpl_image_compare(
     baseline_dir='baseline_images/mpl/test_mpl_integration',
     filename='simple_global.png')
@@ -522,6 +524,7 @@ def test_gridliner_save_tight_bbox():
     fig.savefig(io.BytesIO(), bbox_inches='tight')
 
 
+@pytest.mark.natural_earth
 @pytest.mark.mpl_image_compare(filename='gridliner_labels_title_adjust.png',
                                tolerance=grid_label_tol)
 def test_gridliner_title_adjust():