cli should show a 'new version available' message

[ivanhofer]

It's hard to keep track of new version releases, so I can immagine it would be great if when running the cli while developing, a check for a new version is running in the background and notify users if a new version is avaliable.

While researching I have found this package: update-notifier

These checks should be:

• only made during develoment
• made in the background (no performance implications)
• made once per day (or per week ?)

[ivanhofer]

I had problems getting update-notifier to work. I will not investigate it further.