Insecure CDN's

[metakirby5]

On staging environment, we get this error:

Mixed Content: The page at 'https://sudowoodo-hitmeup-dev-echan.herokuapp.com/user/me/'
was loaded over HTTPS, but requested an insecure stylesheet 'http://fullcalendar.io/js/fullcalendar-
2.3.1/fullcalendar.min.css'. This request has been blocked; the content must be served over HTTPS.

Instead of http://fullcalendar.io/js/fullcalendar-2.3.1/fullcalendar.min.css,

We need to change all our CDN's to the form of //fullcalendar.io/js/fullcalendar-2.3.1/fullcalendar.min.css

[richard1]

Fixed with 7db815b