add year filter to engines with time range support && tests

Following engines does not support "Last year":
 * Bing News
 * DeviantArt
 * DuckDuckGo
 * Yahoo
 * YouTube (noapi)

searx/engines/bing_news.py

@@ -66,6 +66,9 @@ def _get_url(query, language, offset, time_range):
 
 # do search-request
 def request(query, params):
+    if params['time_range'] and params['time_range'] not in time_range_dict:
+        return params
+
     offset = (params['pageno'] - 1) * 10 + 1
 
     if params['language'] == 'all':

searx/engines/deviantart.py

@@ -34,6 +34,9 @@ time_range_dict = {'day': 11,
 
 # do search-request
 def request(query, params):
+    if params['time_range'] and params['time_range'] not in time_range_dict:
+        return params
+
     offset = (params['pageno'] - 1) * 24
 
     params['url'] = search_url.format(offset=offset,

searx/engines/duckduckgo.py

@@ -41,6 +41,9 @@ content_xpath = './/a[@class="result__snippet"]'
 
 # do search-request
 def request(query, params):
+    if params['time_range'] and params['time_range'] not in time_range_dict:
+        return params
+
     offset = (params['pageno'] - 1) * 30
 
     if params['language'] == 'all':

searx/engines/yahoo.py

@@ -77,6 +77,9 @@ def _get_language(params):
 
 # do search-request
 def request(query, params):
+    if params['time_range'] and params['time_range'] not in time_range_dict:
+        return params
+
     offset = (params['pageno'] - 1) * 10 + 1
     language = _get_language(params)
 

searx/engines/youtube_noapi.py

@@ -25,7 +25,8 @@ search_url = base_url + '?search_query={query}&page={page}'
 time_range_url = '&sp=EgII{time_range}%253D%253D'
 time_range_dict = {'day': 'Ag',
                    'week': 'Aw',
-                   'month': 'BA'}
+                   'month': 'BA',
+                   'year': 'BQ'}
 
 embedded_url = '<iframe width="540" height="304" ' +\
     'data-src="//www.youtube-nocookie.com/embed/{videoid}" ' +\