Update main.yml

Author: ageitgey

.github/workflows/main.yml

@@ -5,7 +5,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.8, 3.9, 3.10]
+        python-version: [3.8, 3.9, "3.10"]
     steps:
     - name: Checkout
       uses: actions/checkout@v2