Minimal pomodoro timer for UNIX-like operating systems. Unlike other timers,
uair simply prints the remaining time to standard output. Other than making the
code more maintainable, this design allows uair to be very extensible as it can
be used in various status bars and even command-line and graphical user
interfaces.

Features
- Extensible: Can be used in status bars, desktop widgets, CLIs, GUIs, etc.
- Keyboard-driven: Uses uairctl command-line utility for pausing/resuming the
  timer. It can be binded to a keyboard shortcut.
- Resource-efficient: Uses concurrency instead of spawing multiple threads.
- Multiple synchronized timers: Multiple synchronized uair timers can co-exist
  while sharing a single handle
- Minimal: It adheres to the UNIX philosophy of focusing in doing one thing,
  and doing it well.