Skip macos for now, need to investigate how Mono is installed there

Author: filmor

.github/workflows/ci.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ubuntu-latest, windows-latest, macos-latest]
+        os: [ubuntu-latest, windows-latest] # macos-latest
         python: ['3.9', '3.8', '3.7', '3.6', pypy3]
 
     steps: