Add example of retrieving / streaming historical data

historical_data_example.py

@@ -0,0 +1,18 @@
+from datetime import datetime, timedelta
+from dotenv import load_dotenv
+from os import getenv
+from tastytrade import Tastytrade
+
+load_dotenv()
+account = getenv("TASTYTRADE_ACCOUNT")
+username = getenv("TASTYTRADE_USERNAME")
+password = getenv("TASTYTRADE_PASSWORD")
+
+tastytrade = Tastytrade(username, password)
+tastytrade.login()
+
+tastytrade.stream_historical_data(
+    symbol = 'SPX', 
+    period = 1, type = 'd', 
+    from_time = datetime.now() - timedelta(days = 365)
+)