Add simple depends_on API.

recipes.py

Index: recipes.py
diff --git a/recipes.py b/recipes.py
index d243cc268aad05b7704b69290c48c57a78aac018..40f69bd842f53d36648a69bc278e79732c3d4d3f 100755
--- a/recipes.py
+++ b/recipes.py
@@ -31,7 +31,12 @@ def get_package_config(args):
 
 def simulation_test(package_deps, args):
   from recipe_engine import simulation_test
-  simulation_test.main(package_deps, args=json.loads(args.args))
+  from recipe_engine import loader
+
+  _, config_file = get_package_config(args)
+  universe = loader.RecipeUniverse(package_deps, config_file.path)
+
+  simulation_test.main(universe, args=json.loads(args.args))
 
 
 def lint(package_deps, args):
@@ -108,7 +113,8 @@ def run(package_deps, args):
   os.environ['PYTHONUNBUFFERED'] = '1'
   os.environ['PYTHONIOENCODING'] = 'UTF-8'
 
-  universe = loader.RecipeUniverse(package_deps)
+  _, config_file = get_package_config(args)
+  universe = loader.RecipeUniverse(package_deps, config_file.path)
 
   workdir = (args.workdir or
       os.path.join(os.path.dirname(os.path.realpath(__file__)), 'workdir'))
@@ -126,7 +132,7 @@ def run(package_deps, args):
   finally:
     os.chdir(old_cwd)
 
-  return handle_recipe_return(ret, args.result_file, stream)
+  return handle_recipe_return(ret, args.output_result_json, stream)
 
 
 def roll(args):
@@ -263,7 +269,7 @@ def main():
       '--workdir',
       help='The working directory of recipe execution')
   run_p.add_argument(
-      '--result-file',
+      '--output-result-json',
       help='The file to write the JSON serialized returned value \
             of the recipe to')
   run_p.add_argument(