Add support for Python 3.10

Quotes are needed so the number isn't read as a float and interpreted as 3.1!

https://dev.to/hugovk/the-python-3-1-problem-85g

Author: hugovk

.github/workflows/deploy.yml

@@ -29,7 +29,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v2
         with:
-          python-version: 3.10
+          python-version: "3.10"
 
       - name: Install dependencies
         run: |