temporary: do not waste time on MacOS

Author: penguinolog

.github/workflows/pythonpackage.yml

@@ -9,7 +9,7 @@ jobs:
     strategy:
       max-parallel: 4
       matrix:
-        os: [ubuntu-latest, windows-latest, macOS-latest]
+        os: [ubuntu-latest, windows-latest]
         python-version: [3.6, 3.7]
 
     steps: