Add 3.12 testing to github CI (#33)

diff --git a/.github/workflows/python-package.yml b/.github/workflows/python-package.yml
index 0874933..af3d922 100644
--- a/.github/workflows/python-package.yml
+++ b/.github/workflows/python-package.yml
@@ -18,7 +18,7 @@
     strategy:
       fail-fast: false
       matrix:
-        python-version: [3.7, 3.8, 3.9, '3.10', '3.11.0-beta - 3.11']
+        python-version: [3.7, 3.8, 3.9, '3.10', '3.11', '3.12.0-beta - 3.12']
 
     steps:
       - uses: actions/checkout@v3
@@ -42,7 +42,7 @@
     strategy:
       fail-fast: false
       matrix:
-        python-version: [3.7, 3.8, 3.9, '3.10', '3.11.0-beta - 3.11']
+        python-version: [3.7, 3.8, 3.9, '3.10', '3.11', '3.12.0-beta - 3.12']
 
     steps:
       - uses: actions/checkout@v3