You can test the regular expression in the browser by typing this into the console:
var whiteListIframe = require('pretty-text/sanitizer').whiteListIframe;
whiteListIframe(/^(https?:)?\/\/wearefairphone\.github\.io\/fprsmap/i);
If you’ve got the regular expression right, you’ll see the iframe in the preview window, but not in the cooked post.
