Update appveyor.yml

Author: DocMT

appveyor.yml

@@ -1,14 +1,16 @@
 build: false
 
 environment:
-    matrix:
-        - PYTHON: "C:\\Python39-x64"
-          PYTHON_VERSION: "3.9.13"
-          PYTHON_ARCH: "64"
+  matrix:
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2022
+    - PYTHON: "C:\Python38-x64"
+    - PYTHON: "C:\Python39-x64"
+    - PYTHON: "C:\Python310-x64"
 init:
-  - "ECHO %PYTHON% %PYTHON_VERSION% %PYTHON_ARCH%"
+  - "ECHO %PYTHON%
 
 install:
+  - "%PYTHON%/python.exe -m pip install --upgrade pip"
   - "%PYTHON%/python.exe -m pip install pytest"
   - "%PYTHON%/python.exe -m pip install numpy"
   - "%PYTHON%/python.exe -m pip install scipy"