Addresses proposed fixes on #3

[AntDavidLima]

Addresses fixes proposed on @MyNameIsCosmo's PR and allow the last desktop to be closed when there is another empty desktop focused, if the focused desktop is the penultimate one.

Also enables Go dependency tracking on the project.

I created this fork from @MyNameIsCosmo's fork, but decided to PR to the main repository, since the fork don't receive update for a long time.

I know this repository don't receive updates for some time too, but it would be great if you could merge this PR, since it's a great quality of life update and some people, like me, NEED this application to be able to use BSPWM properly.