Add commando.io service

Hi,

This PR is for adding the official [commando.io](https://commando.io/) service integration :bulb: 

:information_source:  Summary: 

> _Commando.io_ is a simpler way to manage servers online. Commando.io makes it simple to execute commands on groups of servers from a beautiful web interface.

With this service integration, GitHub/Commando.io users can run executions from a simple git push to their :octocat: repository.

I'm the official maintainer :guardsman: so let me know if you have any :interrobang: or require any changes :smile_cat: 

Thanks!