Remove windows testing for now

I'll need to debug and test this in a separate project before adding this back to this repo.

Author: jamesls

.github/workflows/run-tests.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ubuntu-latest, windows-2019]
+        os: [ubuntu-latest]
         python-version: [2.7, 3.5, 3.6, 3.7, 3.8]
 
     steps: