Removed the WebDownload AfterBuild task
Removed the WebDownload AfterBuild task

Tavis-CI is failing on executing the WebDownload task, and it might not
be necessary for Travis-CI as it is only intended to install NuGet if it
isn't already installed, and Travis-CI already seems to have NuGet
installed on its containers.

sendwithus/sendwithus_csharp