Merge pull request #24 from dstephens99/issue22

BUG: Fix crash on empty table

Author: davidastephens

pandas_datareader/data.py

@@ -701,9 +701,6 @@ def _option_frames_from_url(self, url):
         calls = frames[self._TABLE_LOC['calls']]
         puts = frames[self._TABLE_LOC['puts']]
 
-        if len(calls) == 0 or len(puts) == 0:
-            raise RemoteDataError('Received no data from Yahoo at url: %s' % url)
-
         calls = self._process_data(calls, 'call')
         puts = self._process_data(puts, 'put')