Notify If New Version Available

[frankgreco]

It is useful to notify the user if a new version of kanalictl is available.

Here is an example of how Minikube does it:

There is a file called last_update_check that keeps track of the last time a user was notified of a new version. On a certain interval, it will check to see if a user is using the latest version and if not, prompt with the following text:

There is a newer version of minikube available (v24.0).  Download it here: https://foo.bar.com/v24.0

Proposed Solution:
Minic Minikube's behavior. The last_update_check file would live in ~/.kanalictl/. The check would occur on every kanalictl command. The interval at which this check is preformed can be discussed.