Centralize algorithm imports

Algorithm.Python/ExtendedMarketTradingRegressionAlgorithm.py

@@ -1,4 +1,4 @@
-# QUANTCONNECT.COM - Democratizing Finance, Empowering Individuals.
+# QUANTCONNECT.COM - Democratizing Finance, Empowering Individuals.
 # Lean Algorithmic Trading Engine v2.0. Copyright 2014 QuantConnect Corporation.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -11,16 +11,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from clr import AddReference
-AddReference("System")
-AddReference("QuantConnect.Common")
-AddReference("QuantConnect.Algorithm")
-
-import datetime
-from System import *
-from QuantConnect import *
-from QuantConnect.Orders import *
-from QuantConnect.Algorithm import QCAlgorithm
+from AlgorithmImports import *
 
 ### <summary>
 ### This algorithm demonstrates extended market hours trading.
@@ -58,7 +49,7 @@ class ExtendedMarketTradingRegressionAlgorithm(QCAlgorithm):
 
     def InMarketHours(self):
         now = self.Time.time()
-        open = datetime.time(9,30,0)
-        close = datetime.time(16,0,0)
+        open = time(9,30,0)
+        close = time(16,0,0)
         return (open < now) and (close > now)