Update tests: fix tests to cope with Future impl changes

Author: darkjh

tests/futures/test_futures.py

@@ -3,7 +3,7 @@
 
 
 from simpleflow import futures
-from simpleflow.futures import Future
+from simpleflow.swf.futures import Future
 
 
 def test_future_init_state():

tests/test_dataflow.py

@@ -118,7 +118,7 @@ class TestDefinition(TestWorkflow):
     """
     def run(self):
         a = self.submit(increment, 1)
-        assert isinstance(a, futures.Future)
+        assert isinstance(a, futures.AbstractFuture)
 
         b = self.submit(double, a)