Modified the build file to download the latest version of NuGet (in this case, 3.0)

build.ps1

@@ -82,7 +82,7 @@ if ((Test-Path $PSScriptRoot) -and !(Test-Path $TOOLS_DIR)) {
 # Try download NuGet.exe if not exists
 if (!(Test-Path $NUGET_EXE)) {
     Write-Verbose -Message "Downloading NuGet.exe..."
-    Invoke-WebRequest -Uri http://nuget.org/nuget.exe -OutFile $NUGET_EXE
+    Invoke-WebRequest -Uri https://dist.nuget.org/win-x86-commandline/latest/nuget.exe -OutFile $NUGET_EXE
 }
 
 # Make sure NuGet exists where we expect it.