fix python version name

Author: Paul K. Korir, PhD

.github/workflows/python-package.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [ 3.6, 3.7, 3.8, 3.9, 3.10 ]
+        python-version: [ 3.6, 3.7, 3.8, 3.9, '3.10' ]
 
     steps:
       - uses: actions/checkout@v2