function pathItem(match, key) {
        if (params.hasOwnProperty(key) === false) {
            throw new Error(
                'Route <' + routeName + '> is missing parameter <' + key + '>'
            );
        }
        return '/' + encodeURIComponent(params[key]);
    }
Takes an object of route params and query params, and 'renders' a URL.

@public
@function render
@param    {String} routeName - the route name
@param    {Object} params -    an object of route params
@param    {Object} query -     an object of query params
@returns  {String} URL
@example
server.get({
     name: 'cities',
     path: '/countries/:name/states/:state/cities'
}, (req, res, next) => ...));
let cities = server.router.render('cities', {
     name: 'Australia',
     state: 'New South Wales'
});
// cities:  '/countries/Australia/states/New%20South%20Wales/cities'