app/assets/javascripts/pages/participants_edit.js
$(document).on('turbolinks:load', function() {
$('.url').blur(function() {
var self = this;
$(self).val($(self).val().toLowerCase());
var url = $(self).val();
if (url && (url.substr(0,7) !== 'http://') && (url.substr(0,8) !== 'https://')){
$(self).val('https://' + url);
}
});
});