Use the Github email when doing Git pushes from AppVeyor.

appveyor.yml

@@ -55,7 +55,7 @@ build_script:
 
 on_success:
   - git config --global user.name "CppSharp CI"
-  - git config --global user.email "cppsharp-ci@tritao.eu"
+  - git config --global user.email "joao+cppsharp-ci@tritao.eu"
   - git config --global credential.helper store
   - ps: Add-Content "$env:USERPROFILE\.git-credentials" "https://$($env:GITHUB_ACCESS_TOKEN):x-oauth-basic@github.com`n"
   - git remote set-url origin https://github.com/mono/CppSharp.git