Fix AppVeyor issue

appveyor.yml

@@ -26,7 +26,6 @@ init:
 install:
 - "SET PATH=%PYTHON%;%PYTHON%\\Scripts;%PATH%"
 - where pip
-- "%PYTHON%\\python.exe -m pip install --upgrade --user pip"
 - pip install --upgrade setuptools wheel
 - pip install -r requirements.txt
 - pip install --no-deps -r req_nodeps.txt