Refactor test_logo to use mpl_image_compare and track png files in dvc

Author: weiji14

pygmt/tests/baseline/.gitignore

@@ -0,0 +1 @@
+/test_*.png

pygmt/tests/baseline/test_logo.png

@@ -0,0 +1,4 @@
+outs:
+- md5: 905d5b9f0f8d8b809899dfe9e87d0e91
+  size: 33347
+  path: test_logo.png

pygmt/tests/baseline/test_logo.png.dvc

@@ -0,0 +1,4 @@
+outs:
+- md5: 25854f87e4e6f4c30be71bc08a3d430c
+  size: 114522
+  path: test_logo_on_a_map.png

pygmt/tests/baseline/test_logo_on_a_map.png

@@ -1,34 +1,26 @@
 """
 Tests for fig.logo.
 """
+import pytest
 from pygmt import Figure
-from pygmt.helpers.testing import check_figures_equal
 
 
-@check_figures_equal()
+@pytest.mark.mpl_image_compare
 def test_logo():
     """
     Plot a GMT logo of a 2 inch width as a stand-alone plot.
     """
-    fig_ref, fig_test = Figure(), Figure()
-    # Use single-character arguments for the reference image
-    fig_ref.logo(D="x0/0+w2i")
-    fig_test.logo(position="x0/0+w2i")
-    return fig_ref, fig_test
+    fig = Figure()
+    fig.logo(position="x0/0+w2i")
+    return fig
 
 
-@check_figures_equal()
+@pytest.mark.mpl_image_compare
 def test_logo_on_a_map():
     """
     Plot a GMT logo in the upper right corner of a map.
     """
-    fig_ref, fig_test = Figure(), Figure()
-    # Use single-character arguments for the reference image
-    fig_ref.coast(R="-90/-70/0/20", J="M6i", G="chocolate", B="")
-    fig_ref.logo(D="jTR+o0.1i/0.1i+w3i", F="")
-
-    fig_test.coast(
-        region=[-90, -70, 0, 20], projection="M6i", land="chocolate", frame=True
-    )
-    fig_test.logo(position="jTR+o0.1i/0.1i+w3i", box=True)
-    return fig_ref, fig_test
+    fig = Figure()
+    fig.coast(region=[-90, -70, 0, 20], projection="M6i", land="chocolate", frame=True)
+    fig.logo(position="jTR+o0.1i/0.1i+w3i", box=True)
+    return fig