message: Improve AppVeyor config
  Format PS version
  Use web provided script for Yarn install
diff: @@ -23,19 +23,10 @@ init:
  - node --version
  - npm --version
  - yarn --version
  - - ps: $PSVersionTable.PSVersion
  + - ps: $PSVersionTable.PSVersion -f ''
  install:
  # Install the latest version of Yarn
  - - ps: >-
  - Write-Host "Installing Yarn!"
  -
  - $webClient = New-Object Net.WebClient
  -
  - $latestVersion = $webClient.DownloadString('https://yarnpkg.com/latest-version')
  -
  - $webClient.DownloadFile("https://github.com/yarnpkg/yarn/releases/download/v$latestVersion/yarn-$latestVersion.msi", "$env:temp\yarn.msi")
  -
  - cmd /c start /wait msiexec.exe /i $env:temp\yarn.msi /quiet /qn /norestart
  + - ps: curl -o $env:temp\install.ps1 https://raw.githubusercontent.com/JimiC/ps-yarn-install/master/install.ps1 | powershell $env:temp\install.ps1
  # Install modules
  - yarn install
  cache:
  