Updated appveyor cfg

Author: Panos

.appveyor.yml

@@ -13,10 +13,10 @@ environment:
     PYPI_PASS:
       secure: uXkrTaPGSNQdXTJIt3aiy2E1GBnbn6gH3opi7DgMIcmpLgZt7RTeqsaszbjPToGkoqfVXN+jdkQca4LfGAKZ8a2LgrrVYoITdxbjNkZB3yDBKk6ULNMsqdHmt4I1evRhSPSSZnRKU2rSzL+gOTViEVnhcahsUJPgNAIFvpZWsZfdRAafFtF1D33B03aAPwuhYuZTIwRyhUrwVGsYzOzIoDLtnpGj/0+GHazwjhHXfg/yTd600SPiWVsgknxjoeBu+cmi2iMDeT3ULu3P8UGjuQ==
     # Default python version to run single commands with
-    PYTHON_DEF: "C:\\Python36-x64"
-    PYTHON_VERSION: "3.6"
+    PYTHON_DEF: "C:\\Python38-x64"
+    PYTHON_VERSION: "3.8"
     # Python versions to build wheels for
-    PYTHONVERS: C:\Python36-x64 C:\Python37-x64 C:\Python38-x64
+    PYTHONVERS: C:\Python36-x64 C:\Python37-x64 C:\Python38-x64 C:\Python39-x64
     PYTHON_ARCH: "64"
     MSVC: "Visual Studio 14 Win64"