[fix] remove unused imports ++ pep8

searx/engines/google_news.py

 from urllib import urlencode
 from json import loads
 from dateutil import parser
-from datetime import datetime
 
 categories = ['news']
 

searx/engines/vimeo.py

 from HTMLParser import HTMLParser
 from lxml import html
 from xpath import extract_text
-from datetime import datetime
 from dateutil import parser
 
 base_url = 'http://vimeo.com'
         url = base_url + result.xpath(url_xpath)[0]
         title = p.unescape(extract_text(result.xpath(title_xpath)))
         thumbnail = extract_text(result.xpath(content_xpath)[0])
-        publishedDate = parser.parse(extract_text(result.xpath(publishedDate_xpath)[0]))
+        publishedDate = parser.parse(extract_text(
+            result.xpath(publishedDate_xpath)[0]))
 
         results.append({'url': url,
                         'title': title,

searx/engines/youtube.py

 from json import loads
 from urllib import urlencode
 from dateutil import parser
-from datetime import datetime
 
 categories = ['videos']