* modular, object oriented design
* flesh out test suite, mock pypi interaction (which mocking package?)
* use regex to parse requirements lines
* multiprocessing support, workers == cores
* up to date requirements on stdout
* outdated requirements on stderr
* logging support (with a syslog handler), so suitable for cron use
* subcommand support, e.g. piprot-upgrade(receives processed requirements) which outputs a new requirements file with updated versions!
  * this would be useful for automating CI builds of your project against cutting-edge requirements, alerting you to upcoming problems.
