Removed old win/mac versions as Github schedules them slowly

Author: rickardp

.github/workflows/python-package.yml

@@ -23,6 +23,10 @@ jobs:
             python-version: 3.5
           - os: windows-latest
             python-version: 3.5
+          - os: macos-latest
+            python-version: 3.6
+          - os: windows-latest
+            python-version: 3.6
     steps:
     - uses: actions/checkout@v2
     - name: Set up Python ${{ matrix.python-version }}