Added a solution file to group the main and test projects together which should make it easier for apprentices to open the projects in Visual Studio as well as allowing building both projects as a group and running the tests from the root folder on the command line
Added missing BowlingGameTests.cs file to make it consistent with the Java project
Also, fixed author for my original commit as I hadn't changed my global git config
BowlingGameTests.cs
file to make it consistent with the Java project