Add better documentation, trigger namedtuple.

recipe_engine/stream.py

Index: recipe_engine/stream.py
diff --git a/recipe_engine/stream.py b/recipe_engine/stream.py
index 5eaced0d8cf0775f2631566264640a141d7df261..ce98d2079e88cc4d5f1a3ad443221e681992d483 100644
--- a/recipe_engine/stream.py
+++ b/recipe_engine/stream.py
@@ -72,7 +72,7 @@ class StreamEngine(object):
   def make_step_stream(self, name, **kwargs):
     """Shorthand for creating a step stream from a step configuration dict."""
     kwargs['name'] = name
-    return self.new_step_stream(recipe_api._make_step_config(**kwargs))
+    return self.new_step_stream(recipe_api.StepConfig.create(**kwargs))
 
   def new_step_stream(self, step_config):
     """Creates a new StepStream in this engine.