Creating a key prefix also creates an object with the same name

[deviantintegral]

If you create a key prefix, such as 'my-folder/', and then check to see if the key 'my-folder' exists, fakes3 returns an object for the key instead of a 404. This breaks clients that are doing directory operations, as if they create a directory, but then checks to see if the key is a file or a directory, the client sees a file.