previous_day_bar: use Aggsv2 instead of Bar

Author: Devination

alpaca_trade_api/polygon/rest.py

@@ -6,7 +6,6 @@
     Exchange, SymbolTypeMap, ConditionMap,
     Company, Dividends, Splits, Earnings, Financials, NewsList, Ticker
 )
-from ..entity import Bar
 from alpaca_trade_api.common import get_polygon_credentials
 
 
@@ -110,8 +109,8 @@ def last_quote(self, symbol):
 
     def previous_day_bar(self, symbol):
         path = '/aggs/ticker/{}/prev'.format(symbol)
-        raw = self.get(path, version='v2')['results'][0]
-        return Bar(raw)
+        raw = self.get(path, version='v2')
+        return Aggsv2(raw)
 
     def condition_map(self, ticktype='trades'):
         path = '/meta/conditions/{}'.format(ticktype)