Templates out of date

[dansiegel]

Description

Upon creating a new Device Runner from the Android template in Visual Studio, the xunit.runner.devices package fails to install due to the Android template targeting v6 Marshmellow instead of 8.1 Oreo...

Also when looking at the custom writer section of the template, it shows using the Writer with the TcpTextWriter, however the Writer has been marked obsolete. This should be updated to use the new ResultChannel instead.