Add dotnet clean workaround to TESTS.md (#221)
Add dotnet clean workaround to TESTS.md (#221)

* Add dotnet clean workaround to TESTS.md

* Update TESTS.md

ErikSchierboom/xcsharp,ErikSchierboom/xcsharp,robkeim/xcsharp,exercism/xcsharp,GKotfis/csharp,GKotfis/csharp,exercism/xcsharp,robkeim/xcsharp