fix python specification

Author: sarahmish

.github/workflows/tests.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        python-version: [3.10]
+        python-version: ['3.10']
         os: [ubuntu-latest]
     steps:
     - uses: actions/checkout@v1