MAINT: Removes unused init method from algorithm.

The init method had been copied to method called initialize,
to avoid confusion with __init__

zipline/algorithm.py

@@ -313,10 +313,6 @@ class TradingAlgorithm(object):
             "Algorithm should have a utc datetime"
         return date_copy
 
-    def init(self, *args, **kwargs):
-        """Called from constructor."""
-        pass
-
     def set_transact(self, transact):
         """
         Set the method that will be called to create a