- encourage use of make_app() (makes testing easier)
- use fully-qualified module paths (painful in real-world code,
but makes examples clearer)
- don't define a main() function that is never called: just
use a boring old "__name__ == __main__" block, so the code
can be copy + pasted + executed immediately
- just use a tuple when defining routes, not url(...): this is
supposed to be a simple, minimalist example
Ben Darnell