Asynchronously copies a file or directory recursively from source to destination path

Example

FileSystem = require("FuseJS/FileSystem");

FileSystem.writeTextToFile("to-be-copied.txt", "hello world")
    .then(function() {
        return FileSystem.copy("to-be-copied.txt", "destination-reached.txt");
    })
    .catch(function(err) {
        console.log("Unable to copy file");
    });