Bring back access tokens for AzP feed access

Fixes #49 (properly)

azure-pipelines/install-dependencies.yml

@@ -4,7 +4,8 @@ parameters:
 steps:
 
 - powershell: |
-    .\init.ps1 ${{ parameters['initArgs'] }} -UpgradePrerequisites
+    $AccessToken = '$(System.AccessToken)' # Avoid specifying the access token directly on the init.ps1 command line to avoid it showing up in errors
+    .\init.ps1 -AccessToken $AccessToken ${{ parameters['initArgs'] }} -UpgradePrerequisites
     dotnet --info
   displayName: Install prerequisites