Built using dotnet new.
To publish, use dotnet publish and you can choose to built to an executable, or just do dotnet RomanCalc.dll wherever that file ends up getting built.
To build an exe for macOS: dotnet publish --runtime osx.10.11-x64.
To test run dotnet test.
RomanCalc can accept a newline delimited file or you can pass arguments directly.
RomanCalc test.txt or RomanCalc 123 or RomanCalc MCMXCII should all work.
If you don't pass anything, it will ask for a path or argument and will then parse and return.