Remove comments and improve logging

lib/crawler.js

@@ -13,18 +13,18 @@ class Crawler {
 
   start() {
     return this.queue.pop()
-      .catch()
       .then(this._convertToRequest.bind(this))
-      .then((request) => {
-        console.log(request.crawl.url);
+      .then(this._filterSeen.bind(this))
+      .then(request => {
+        if (request) {
+          this.logger.log('info', `${request.crawl.url} [${request.crawl.type}]`);
+        }
         return request;
       })
-      .then(this._filterSeen.bind(this))
       .then(this._fetch.bind(this))
       .then(this._convertToDocument.bind(this))
       .then(this._processDocument.bind(this))
       .then(this._storeDocument.bind(this))
-      .catch()
       .then(this._deleteFromQueue.bind(this))
       .then(this._markSeen.bind(this))
       .then(this._startNext.bind(this));