Switching to nuget 5.3.1. Should address some CredentialProvider issues we are seeing. (#320)

Author: agr

build/common.ps1

@@ -434,7 +434,7 @@ Function Install-NuGet {
 
             Trace-Log 'Downloading nuget.exe'
             Invoke-WebRequest `
-                https://dist.nuget.org/win-x86-commandline/v5.3.0/nuget.exe `
+                https://dist.nuget.org/win-x86-commandline/v5.3.1/nuget.exe `
                 -UseBasicParsing `
                 -OutFile $NuGetExe