Just a heads-up, if a user neglects to put a name into their profile, then clicking on the “Claim Certificate” button for the Responsive Web Design unit does nothing. No error in the UI and no visual indicator that nothing worked. If you go into Chrome’s developer console and look at the requests and responses, the following text is visible in the preview:
message:"We need your name so we can put it on your certification.↵Add your name to your account settings and click the save button.↵Then we can issue your certification." success:false
Adding my name into my profile fixed the issue and allowed claiming of the certificate.