Simplify Train (C#) folder structure

91_Train/csharp/Train/Train.sln

@@ -1,31 +0,0 @@
-
-Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio Version 16
-VisualStudioVersion = 16.0.31129.286
-MinimumVisualStudioVersion = 10.0.40219.1
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TrainGame", "Train\TrainGame.csproj", "{42617537-4E7C-4082-A17B-7F18DFA04C35}"
-EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TrainTests", "..\TrainTests\TrainTests\TrainTests.csproj", "{7C740A47-99C6-44E1-BDEE-140086BCFE8B}"
-EndProject
-Global
-	GlobalSection(SolutionConfigurationPlatforms) = preSolution
-		Debug|Any CPU = Debug|Any CPU
-		Release|Any CPU = Release|Any CPU
-	EndGlobalSection
-	GlobalSection(ProjectConfigurationPlatforms) = postSolution
-		{42617537-4E7C-4082-A17B-7F18DFA04C35}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{42617537-4E7C-4082-A17B-7F18DFA04C35}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{42617537-4E7C-4082-A17B-7F18DFA04C35}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{42617537-4E7C-4082-A17B-7F18DFA04C35}.Release|Any CPU.Build.0 = Release|Any CPU
-		{7C740A47-99C6-44E1-BDEE-140086BCFE8B}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{7C740A47-99C6-44E1-BDEE-140086BCFE8B}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{7C740A47-99C6-44E1-BDEE-140086BCFE8B}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{7C740A47-99C6-44E1-BDEE-140086BCFE8B}.Release|Any CPU.Build.0 = Release|Any CPU
-	EndGlobalSection
-	GlobalSection(SolutionProperties) = preSolution
-		HideSolutionNode = FALSE
-	EndGlobalSection
-	GlobalSection(ExtensibilityGlobals) = postSolution
-		SolutionGuid = {919F73B8-DE34-4992-9B05-E1FEC2D2F7C6}
-	EndGlobalSection
-EndGlobal