[recipes.py] use argparse to set command automatically.

recipe_engine/test.py

 # Copyright 2017 The LUCI Authors. All rights reserved.
 # Use of this source code is governed under the Apache License, Version 2.0
 # that can be found in the LICENSE file.
 
 from __future__ import print_function
 
 import bdb
 import cStringIO
 import contextlib
 import copy
@@ skipping 904 matching lines @@
     '--filter', action='append', type=normalize_filter,
     help=glob_helpstr)
 
   def postprocess_func(_parser, args):
     # Auto-enable bootstrap for test command invocations (necessary to get
     # recent enough version of coverage package), unless explicitly disabled.
     if args.use_bootstrap is None:
       args.use_bootstrap = True
 
   test_p.set_defaults(
-    command='test', func=main,
-    postprocess_func=postprocess_func,
+    func=main, postprocess_func=postprocess_func,
   )
 
 
 def main(package_deps, args):
   """Runs simulation tests on a given repo of recipes.
 
   Args:
     package_deps (PackageDeps)
     args: the parsed args (see add_subparser).
   Returns:
     Exit code
   """
   universe = loader.RecipeUniverse(package_deps, args.package)
   universe_view = loader.UniverseView(universe, package_deps.root_package)
   engine_flags=args.operational_args.engine_flags
 
   # Prevent flakiness caused by stale pyc files.
   package.cleanup_pyc(package_deps.root_package.recipes_dir)
 
   global _UNIVERSE_VIEW
   _UNIVERSE_VIEW = universe_view
   global _ENGINE_FLAGS
   _ENGINE_FLAGS = engine_flags
 
   return args.subfunc(args)