Update 'requests' lib to v2.0.

third_party/requests/packages/urllib3/_collections.py

 # urllib3/_collections.py
 # Copyright 2008-2013 Andrey Petrov and contributors (see CONTRIBUTORS.txt)
 #
 # This module is part of urllib3 and is released under
 # the MIT License: http://www.opensource.org/licenses/mit-license.php
 
 from collections import MutableMapping
-from threading import Lock
+from threading import RLock
 
 try: # Python 2.7+
     from collections import OrderedDict
 except ImportError:
     from .packages.ordered_dict import OrderedDict
 
 
 __all__ = ['RecentlyUsedContainer']
 
 
@@ skipping 14 matching lines @@
         ``dispose_func(value)`` is called.  Callback which will get called
     """
 
     ContainerCls = OrderedDict
 
     def __init__(self, maxsize=10, dispose_func=None):
         self._maxsize = maxsize
         self.dispose_func = dispose_func
 
         self._container = self.ContainerCls()
-        self._lock = Lock()
+        self.lock = RLock()
 
     def __getitem__(self, key):
         # Re-insert the item, moving it to the end of the eviction line.
-        with self._lock:
+        with self.lock:
             item = self._container.pop(key)
             self._container[key] = item
             return item
 
     def __setitem__(self, key, value):
         evicted_value = _Null
-        with self._lock:
+        with self.lock:
             # Possibly evict the existing value of 'key'
             evicted_value = self._container.get(key, _Null)
             self._container[key] = value
 
             # If we didn't evict an existing value, we might have to evict the
             # least recently used item from the beginning of the container.
             if len(self._container) > self._maxsize:
                 _key, evicted_value = self._container.popitem(last=False)
 
         if self.dispose_func and evicted_value is not _Null:
             self.dispose_func(evicted_value)
 
     def __delitem__(self, key):
-        with self._lock:
+        with self.lock:
             value = self._container.pop(key)
 
         if self.dispose_func:
             self.dispose_func(value)
 
     def __len__(self):
-        with self._lock:
+        with self.lock:
             return len(self._container)
 
     def __iter__(self):
         raise NotImplementedError('Iteration over this class is unlikely to be threadsafe.')
 
     def clear(self):
-        with self._lock:
+        with self.lock:
             # Copy pointers to all values, then wipe the mapping
             # under Python 2, this copies the list of values twice :-|
             values = list(self._container.values())
             self._container.clear()
 
         if self.dispose_func:
             for value in values:
                 self.dispose_func(value)
 
     def keys(self):
-        with self._lock:
+        with self.lock:
             return self._container.keys()