I wonder how to verify the ssh host key from branchable.com?

:~$ git clone ssh://b-sitename@sitename.branchable.com/ sitename.branchable.com
Initialized empty Git repository in /home/username/sitename.branchable.com/.git/
The authenticity of host 'sitename.branchable.com (xxx.xxx.xxx.xxx)' can't be established.
RSA key fingerprint is 8f:76:a9:90:e3:58:bf:68:cb:3c:80:08:a4:d4:d3:14.
Are you sure you want to continue connecting (yes/no)? 

I've been told that this might be a good opportunity to use Monkeysphere to verify ssh host keys. It uses a PGP web of trust. The Monkeysphere project explains it on their web page.

Otherwise, is there a secure web url for branchable.com that lists various keys for servers?

I'm new to all this my self, but trying to do it right.