Use correct path for Windows and run all Pythons

Signed-off-by: Philippe Ombredanne <pombredanne@nexb.com>

Author: pombredanne

appveyor.yml

@@ -2,16 +2,18 @@ version: '{build}'
 
 environment:
     matrix:
-        - PYTHON_EXE: "C:\\Python36\\python.exe"
         - PYTHON_EXE: "C:\\Python36-x64\\python.exe"
+        - PYTHON_EXE: "C:\\Python37-x64\\python.exe"
+        - PYTHON_EXE: "C:\\Python38-x64\\python.exe"
+        - PYTHON_EXE: "C:\\Python39-x64\\python.exe"
 
 install:
     - configure
 
 build: off
 
 test_script:
-    - 'bin\activate'
-    - 'bin\python -c "from __future__ import print_function;import sys;print(sys.getdefaultencoding())"'
-    - 'bin\py.test -vvs'
+    - 'tmp\Scripts\activate'
+    - 'tmp\Scripts\python -c "from __future__ import print_function;import sys;print(sys.getdefaultencoding())"'
+    - 'tmp\Scripts\py.test -vvs'