[appveyor] redirect stderr for twine inside powershell

otherwise PowerShell thinks it's an error... :(

https://ci.appveyor.com/project/anthrotype/zopfli/build/1.0.21/job/4uefbbr3xn8s6r5a#L105
https://stackoverflow.com/questions/44632416/upload-using-twine-in-appveyor-using-ps

appveyor.yml

@@ -5,8 +5,8 @@ environment:
     # See: http://stackoverflow.com/a/13751649/163740
     CMD_IN_ENV: "cmd /E:ON /V:ON /C %APPVEYOR_BUILD_FOLDER%\\multibuild\\ci\\appveyor\\windows_sdk.cmd"
     # PyPI username and encrypted password
-    PYPI_USER: anthrotype
-    PYPI_PSWD:
+    TWINE_USERNAME: anthrotype
+    TWINE_PASSWORD:
       secure: i3kDZLpYJy081xLBTe0AjA==
 
   matrix:
@@ -89,7 +89,9 @@ on_success:
       if($env:APPVEYOR_REPO_TAG -eq 'true') {
         Write-Output ("Deploying " + $env:APPVEYOR_REPO_TAG_NAME + " to PyPI...")
         pip install --upgrade twine
-        twine upload -u $env:PYPI_USER -p $env:PYPI_PSWD dist\*.whl
+        # If powershell ever sees anything on stderr it thinks it's a fail.
+        # So we use cmd to redirect stderr to stdout before PS can see it.
+        cmd /c 'twine upload dist\*.whl 2>&1'
       } else {
         Write-Output "Not deploying as this is not a tagged commit"
       }

setup.py

@@ -51,7 +51,7 @@ def run(self):
 
 setup(
     name='zopfli',
-    version='0.1.2',
+    version='0.1.3',
     author='Adam DePrince',
     author_email='[email protected]',
     maintainer='Cosimo Lupo',