Add old python versions to tests (#9)

* Update tests.yml

* Update tests.yml

* Update tests.yml

* Update tests.yml

* Update tests.yml

Author: AttackingOrDefending

.github/workflows/tests.yml

@@ -17,6 +17,13 @@ jobs:
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
         python: [3.8, 3.9, "3.10", "3.11", "3.12"]
+        include:
+          - os: macos-13
+            python: 3.7
+          - os: ubuntu-20.04
+            python: 3.7
+          - os: windows-2019
+            python: 3.7
 
     steps:
     - uses: actions/checkout@v3