Add Python 3.10 CI runners

.github/workflows/test.yml

@@ -15,13 +15,13 b' jobs:'
     strategy:
       matrix:
         os: [ubuntu-latest]
-        python-version: ["3.7", "3.8", "3.9"]
+        python-version: ["3.7", "3.8", "3.9", "3.10"]
         # Test all on ubuntu, test ends on macos
         include:
           - os: macos-latest
             python-version: "3.7"
           - os: macos-latest
-            python-version: "3.9"
+            python-version: "3.10"
 
     steps:
     - uses: actions/checkout@v2

appveyor.yml

@@ -4,10 +4,15 b' matrix:'
 
 environment:
   global:
+    APPVEYOR_BUILD_WORKER_IMAGE: 'Visual Studio 2022'
     COLUMNS: 120  # Appveyor web viwer window width is 130 chars
 
   matrix:
 
+   - PYTHON: "C:\\Python310-x64"
+     PYTHON_VERSION: "3.10.x"
+     PYTHON_ARCH: "64"
+
    - PYTHON: "C:\\Python37-x64"
      PYTHON_VERSION: "3.7.x"
      PYTHON_ARCH: "64"