Simplify Mastermind (C#) folder structure

60_Mastermind/csharp/Mastermind.sln

@@ -1,9 +1,9 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio Version 16
+# Visual Studio Version 17
-VisualStudioVersion = 16.0.31321.278
+VisualStudioVersion = 17.0.32014.148
 MinimumVisualStudioVersion = 10.0.40219.1
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Game", "Game\Game.csproj", "{E8D63140-971D-4FBF-8138-964E54CCB7DD}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Mastermind", "Mastermind.csproj", "{AEC839CD-C6D3-4476-AA85-79B160AF78BE}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -11,10 +11,10 @@ Global
 		Release|Any CPU = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(ProjectConfigurationPlatforms) = postSolution
-		{E8D63140-971D-4FBF-8138-964E54CCB7DD}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{AEC839CD-C6D3-4476-AA85-79B160AF78BE}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{E8D63140-971D-4FBF-8138-964E54CCB7DD}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{AEC839CD-C6D3-4476-AA85-79B160AF78BE}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{E8D63140-971D-4FBF-8138-964E54CCB7DD}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{AEC839CD-C6D3-4476-AA85-79B160AF78BE}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{E8D63140-971D-4FBF-8138-964E54CCB7DD}.Release|Any CPU.Build.0 = Release|Any CPU
+		{AEC839CD-C6D3-4476-AA85-79B160AF78BE}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE