Re-enable Windows builds (#518)

Skip test_image on Windows and re-enable Windows CI jobs.

Author: seisman

.github/workflows/ci_tests.yaml

@@ -43,8 +43,7 @@ jobs:
       fail-fast: false
       matrix:
         python-version: [3.6, 3.7, 3.8]
-        #os: [ubuntu-latest, macOS-latest, windows-latest]
-        os: [ubuntu-latest, macOS-latest]
+        os: [ubuntu-latest, macOS-latest, windows-latest]
     # environmental variables used in coverage
     env:
       OS: ${{ matrix.os }}

pygmt/tests/test_image.py

@@ -2,6 +2,7 @@
 Tests image.
 """
 import os
+import sys
 
 import pytest
 
@@ -11,6 +12,7 @@
 TEST_IMG = os.path.join(os.path.dirname(__file__), "baseline", "test_logo.png")
 
 
+@pytest.mark.skipif(sys.platform == "win32", reason="crashes on Windows")
 @pytest.mark.mpl_image_compare
 def test_image():
     "Place images on map"