Modified variable namespace to commandLineInterface for readability.
Set terminal to true to make this TTY.
Set the prompt after the execution of the interpreter engines and I think this is more appropriate because interpreter engines may or may not invoke the prompt method.
Append the workingDirectory value to the cliInterpreterEngineFilePath because the require module look up is not affected by the process.chdir call to workingDirectory.
Added more comments for documentation.