async loadSettings() {
        try {
            const file = await fs.readFile(this.settingFilePath, 'utf8');
            debug('routes settings file found for:', this.settingFilePath);

            const object = this.parseYaml(file);
            debug('YAML settings file parsed:', this.settingFilePath);

            return validate(object);
        } catch (err) {
            if (errors.utils.isGhostError(err)) {
                throw err;
            }

            throw new errors.InternalServerError({
                message: tpl(messages.settingsLoaderError, {
                    setting: 'routes',
                    path: this.settingFilePath
                }),
                err: err
            });
        }
    }
Reads the routes.yaml settings file and passes the
file to the YAML parser which then returns a JSON object.
@returns {Promise<RouteSettings>} settingsFileContents