Remove unused imports and fix some other linter errors.

recipe_engine/unittests/recipe_api_test.py

 #!/usr/bin/env python
 # Copyright 2015 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.
 
-import os
-import sys
 import unittest
 
 import test_env
 
 from recipe_engine import recipe_api, config
 
 def make_prop(**kwargs):
   name = kwargs.pop('name', "dumb_name")
   return recipe_api.Property(**kwargs).bind(name, 'test', 'properties_test')
 
@@ skipping 63 matching lines @@
     Tests setting a param name correctly carries through to a bound property.
     """
     prop = recipe_api.Property(param_name='good_name')
     bound = prop.bind('bad.name-time', 'test', 'test_me')
 
     self.assertEqual('good_name', bound.param_name)
 
 
 if __name__ == '__main__':
   unittest.main()