Check if python 2.6 is functional

Author: itziakos

appveyor.yml

@@ -39,6 +39,7 @@ cache:
 init:
   - ps: $Env:path = $Env:PYTHON + ";" + $Env:PYTHON + "/Scripts;" + $Env:path
 install:
+  - cmd: c:\python26-x64\python.exe -V
   - cmd: python -m pip install -rtox-requirements.txt
 test_script:
   - python -m tox -v