Support VSTS as a package feed

Currently, you can use VSTS as a package feed with the nuget client (https://docs.microsoft.com/en-us/vsts/package/nuget/nuget-exe?view=vsts)

However, trying to proxy a VSTS feed in Artifactory fails, likely because the package download path for the actual package leads to a metadata page? 

-For example, installing directly from vsts:

nuget install VSTS-Helloworld -Source testfeed -Verbosity detailed
NuGet Version: 4.7.0.5148
Feeds used:
https://uriahl.pkgs.visualstudio.com/_packaging/testfeed2/nuget/v2

Installing package 'VSTS-Helloworld' to '/Users/mattheww/Downloads'.
GET https://uriahl.pkgs.visualstudio.com/_packaging/testfeed2/nuget/v2/FindPackagesById()?id='VSTS-Helloworld'&semVerLevel=2.0.0
OK https://uriahl.pkgs.visualstudio.com/_packaging/testfeed2/nuget/v2/FindPackagesById()?id='VSTS-Helloworld'&semVerLevel=2.0.0 553ms

Resolved actions to install package 'VSTS-Helloworld.1.0.2'
Retrieving package 'VSTS-HelloWorld 1.0.2' from 'testfeed'.
GET https://uriahl.pkgs.visualstudio.com/_packaging/testfeed2/nuget/v2/Packages(Id='VSTS-HelloWorld',Version='1.0.2')
OK https://uriahl.pkgs.visualstudio.com/_packaging/testfeed2/nuget/v2/Packages(Id='VSTS-HelloWorld',Version='1.0.2') 404ms
Adding package 'VSTS-HelloWorld.1.0.2' to folder '/Users/mattheww/Downloads'
Added package 'VSTS-HelloWorld.1.0.2' to folder '/Users/mattheww/Downloads'
Added package 'VSTS-HelloWorld.1.0.2' to folder '/Users/mattheww/Downloads' from source 'https://uriahl.pkgs.visualstudio.com/_packaging/testfeed2/nuget/v2'
Successfully installed 'VSTS-HelloWorld 1.0.2' to /Users/mattheww/Downloads

-The metadata is  https://uriahl.pkgs.visualstudio.com/_packaging/testfeed2/nuget/v2/Packages(Id='VSTS-HelloWorld',Version='1.0.2') which returns the following URL presumably as the download url for the actual package:

<content type="application/zip" src="https://uriahl.pkgs.visualstudio.com/_packaging/testfeed2/nuget/v2?id=vsts-helloworld&version=1.0.2" />

-However, viewing in a web browser https://uriahl.pkgs.visualstudio.com/_packaging/testfeed2/nuget/v2?id=vsts-helloworld&amp;version=1.0.2 doesn't download the actual package

It is not clear what the Nuget Download Context Path or the Feed Context Path should be on Artifactory's side