Update nuget packages path and fix E2E tests (#609)

* Update nuget packages path

* Update AspNetVNext value from https://dotnet.myget.org/ to https://www.myget.org/

Author: Francisco-Gamino

NuGet.config

@@ -5,6 +5,6 @@
     <add key="azure_app_service" value="https://www.myget.org/F/azure-appservice/api/v2" />
     <add key="azure_app_service_staging" value="https://www.myget.org/F/azure-appservice-staging/api/v2" />
     <add key="buildTools" value="https://www.myget.org/F/30de4ee06dd54956a82013fa17a3accb/" />
-    <add key="AspNetVNext" value="https://dotnet.myget.org/F/aspnetcore-dev/api/v3/index.json" />
+    <add key="AspNetVNext" value="https://www.myget.org/F/aspnetcore-dev/api/v3/index.json" />
   </packageSources>
 </configuration>

tools/helper.psm1

@@ -131,7 +131,7 @@ function Resolve-ProtoBufToolPath
 {
     if (-not $Script:protoc_Path) {
         Write-Log "Resolve the protobuf tools for auto-generating code"
-        $nugetPath = "~/.nuget/packages"
+        $nugetPath = Get-NugetPackagesPath
         $toolsPath = "$RepoRoot/tools"
 
         if (-not (Test-Path "$toolsPath/obj/project.assets.json")) {
@@ -205,6 +205,23 @@ function Write-Log
     Write-Host -ForegroundColor $foregroundColor "${indentPrefix}${Message}"
 }
 
+function Get-NugetPackagesPath
+{
+    if ($env:NUGET_PACKAGES)
+    {
+        return $env:NUGET_PACKAGES
+    }
+
+    if ($IsWindowsEnv)
+    {
+        return "${env:USERPROFILE}\.nuget\packages"
+    }
+    else
+    {
+        return "${env:HOME}/.nuget/packages"
+    }
+}
+
 #region Start-ResGen
 
 $generated_code_template = @'