fails:File.zero? returns true if the file is empty
fails:File.zero? returns false if the file is not empty
fails:File.zero? accepts an object that has a #to_path method
fails:File.zero? returns true for /dev/null
fails:File.zero? raises an ArgumentError if not passed one argument
fails:File.zero? raises a TypeError if not passed a String type
fails:File.zero? returns true inside a block opening a file if it is empty
fails:File.zero? returns false for a directory
fails:File.zero? returns false if the file does not exist
