CD-18 Expose aws box url

@vasili-zolotov @d3ming 

This creates a link to the aws box that's created during ci. Right now it uses the users github icon as the button, but this can be changed later with a real icon. (I didn't want to take a stab at art)
I'll keep that in mind and implement a more flexible solution if there's ever a need, unless you'd like me to handle it now.