Obtain HTTPS cert for labs.torproject.org
We need an HTTPS certificate to host labs.torproject.org. Right now, we could point the labs.torproject.org domain at the load balancer at live-tor-labs.pantheon.io via CNAME, but that will need to change to an A record as soon as we deploy HTTPS.
Since we know we want HTTPS, we might as well get the cert first, and then create the A record after that.