Add method to validate arguments so application does not wait for input

The application currently waits for input if there are no arguments or options given. I added a method to validate the arguments so it generates a usage statement if executed with no arguments or options. I tested the changes when reading from the command line or a pipe. I also tested with the other options and everything works as before. 

I'm not that familiar with dzil, so I didn't know the best way to add/modify tests and not change your build process.