Since we added the team functionality 6 months ago there were two things missing. Delete a site, and also leave a site by yourself. They are now here to stay.
Now, under site settings, you are able to delete your site. Take into account that this action is not reversible. When you delete your site all the data will disappear including, triggers, configurations, members and statistics.
Also, if you access to the site settings page, you can leave team by yourself.
It's an small change, but you will love it.
Start for free, and upgrade your account at any moment.