Old dotnet-install.ps1 link

Author: nblumhardt

appveyor.yml

@@ -6,7 +6,7 @@ install:
 - ps: $RequiredDotnetVersion =  $(Get-Content ./global.json | ConvertFrom-Json).sdk.version
 - ps: $env:DOTNET_INSTALL_DIR = "$pwd\.dotnetsdk"
 - ps: mkdir $env:DOTNET_INSTALL_DIR -Force | Out-Null
-- ps: Invoke-WebRequest -Uri "https://raw.githubusercontent.com/dotnet/cli/rel/1.0.0/scripts/obtain/dotnet-install.ps1" -OutFile "$($env:DOTNET_INSTALL_DIR)/dotnet-install.ps1"
+- ps: Invoke-WebRequest -Uri "https://dot.net/v1/dotnet-install.ps1" -OutFile "$($env:DOTNET_INSTALL_DIR)/dotnet-install.ps1"
 - ps: '& "$($env:DOTNET_INSTALL_DIR)/dotnet-install.ps1" -Version $RequiredDotnetVersion -InstallDir $env:DOTNET_INSTALL_DIR'
 - ps: $env:Path = "$env:DOTNET_INSTALL_DIR;$env:Path"
 build_script: