Update copyright notice from Swarming to LUCI; add AUTHORS and CONTRIBUTORS.

appengine/swarming/swarming_bot/api/bot.py

-# Copyright 2014 The Swarming Authors. All rights reserved.
+# Copyright 2014 The LUCI Authors. All rights reserved.
 # Use of this source code is governed by the Apache v2.0 license that can be
 # found in the LICENSE file.
 
 """Bot interface used in bot_config.py."""
 
 import logging
 import os
 import threading
 import time
 
@@ skipping 180 matching lines @@
       if t.isAlive():
         logging.error('Timer thread did not terminate fast enough: %s', t)
 
   def update_dimensions(self, new_dimensions):
     """Called internally to update Bot.dimensions."""
     self._attributes['dimensions'] = new_dimensions
 
   def update_state(self, new_state):
     """Called internally to update Bot.state."""
     self._attributes['state'] = new_state