install latest sdk

appveyor.yml

@@ -1,11 +1,18 @@
 
 version: 0.0.{build}
 install:
+  # Use the install script to grab the latest dotnet install
+  - ps: iex .\dotnet-latest.ps1
   - choco install gitversion.portable -pre -y
-  
+  # Prepend newly installed dotnet cli to the PATH of this build (this cannot be
+  # done from inside the powershell script as it would require to restart
+  # the parent CMD process).
+  - "SET PATH=C:\\Program Files\\dotnet\\bin;%PATH%"  
+
 before_build:
-  - ps: gitversion /l console /output buildserver
   - cmd: dotnet --version
+  - ps: gitversion /l console /output buildserver
+
 
 build_script:
   - cmd: build.cmd

dotnet-latest.ps1

@@ -0,0 +1,29 @@
+# Set up everything for using the dotnet cli. This should mean we do not have to wait for Appveyor images to be updated.
+
+# Clean and recreate the folder in which all output packages should be placed
+$ArtifactsPath = "artifacts"
+
+if (Test-Path $ArtifactsPath) { 
+	Remove-Item -Path $ArtifactsPath -Recurse -Force -ErrorAction Ignore 
+}
+
+New-Item $ArtifactsPath -ItemType Directory -ErrorAction Ignore | Out-Null
+
+Write-Host "Created artifacts folder '$ArtifactsPath'"
+
+# Install the latest dotnet cli   
+if (Get-Command "dotnet.exe" -ErrorAction SilentlyContinue) {
+    Write-Host "dotnet SDK already installed"
+	dotnet --version 
+} else {
+    Write-Host "Installing dotnet SDK"
+    
+    $installScript = Join-Path $ArtifactsPath "dotnet-install.ps1"
+    
+	Write-Host $installScript
+
+     Invoke-WebRequest "https://raw.githubusercontent.com/dotnet/cli/rel/1.0.0/scripts/obtain/install.ps1" `
+       -OutFile $installScript
+        
+     & $installScript
+}