Small update to results time period test

Updated to ensure a child span element is available before running a
test to verify the correct time range for the result. Need to come up
with a better way of ensuring uniform results across multiple tests,
since otherwise periodic changes in the returned results can cause tests
to fail.

test/test_results.py

@@ -55,7 +55,7 @@ def test_recent_results(client):
         result_divs = get_search_results(rv.data)
 
         current_date = datetime.now()
-        for div in result_divs:
+        for div in [_ for _ in result_divs if _.find('span')]:
             date_span = div.find('span').decode_contents()
             if not date_span or len(date_span) > 15 or len(date_span) < 7:
                 continue