Update tests.yml

Author: fgregg

.github/workflows/tests.yml

@@ -13,13 +13,11 @@ jobs:
 
     strategy:
       matrix:
-        python-version: ["2.7", "3.6", "3.7", "3.8", "3.9", "3.10", "3.11"]
+        python-version: ["2.7", "3.8", "3.9", "3.10", "3.11", "3.12"]
         os: [ubuntu-latest, macos-latest, windows-latest]
         exclude:
           - os: windows-latest
             python-version: "2.7"
-          - os: ubuntu-latest
-            python-version: "3.6"
       fail-fast: false
 
     steps: