Unable to return Tuple from a method using Visual Studio 2017 and C# 7.0

I Just ran through this page on Roslyn which describes the following steps to get this working:

1. Start a C# project
2. Add a reference to the System.ValueTuple
   package from NuGet (pre-release)

Following those steps, it is now working. But it is really very weird that we need to do that for every single project that we start! Hope this is fixed when we reach the Official release!