Centralize algorithm imports

Algorithm.Python/CustomDataUniverseAlgorithm.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");
@@ -11,17 +11,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from clr import AddReference
-AddReference("System")
-AddReference("QuantConnect.Algorithm")
-AddReference("QuantConnect.Common")
-
-from System import *
-from QuantConnect import *
-from QuantConnect.Algorithm import QCAlgorithm
-from QuantConnect.Data import SubscriptionDataSource
-from QuantConnect.Python import PythonData
-from datetime import date, timedelta, datetime
+from AlgorithmImports import *
 
 ### <summary>
 ### This algorithm shows how to grab symbols from an external api each day
@@ -119,4 +109,4 @@ class NyseTopGainers(PythonData):
         nyse.Symbol = Symbol.Create(symbol_string, SecurityType.Equity, Market.USA)
         nyse["TopGainersRank"] = self.count
         self.count = self.count + 1
-        return nyse
+        return nyse