You are using pip version 8.1.1, however version 8.1.2 is available.
You should consider upgrading via the 'python -m pip install --upgrade pip' command.

C:\Temp>python -m pip install --upgrade pip
Collecting pip
  Using cached pip-8.1.2-py2.py3-none-any.whl
Installing collected packages: pip
  Found existing installation: pip 8.1.1
    Uninstalling pip-8.1.1:
Exception:
Traceback (most recent call last):
  File "C:\Program Files\Python35\lib\shutil.py", line 538, in move
    os.rename(src, real_dst)
PermissionError: [WinError 5] Access denied: 'c:\\program files\\python35\\lib\\site-packages\\pip-8.1.1.dist-info\\description.rst' -> 'C:\\Users\\sysop\\Temp\\pip-az7w4les-uninstall\\program file
s\\python35\\lib\\site-packages\\pip-8.1.1.dist-info\\description.rst'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "C:\Program Files\Python35\lib\site-packages\pip\basecommand.py", line 209, in main
    status = self.run(options, args)
  File "C:\Program Files\Python35\lib\site-packages\pip\commands\install.py", line 317, in run
    prefix=options.prefix_path,
  File "C:\Program Files\Python35\lib\site-packages\pip\req\req_set.py", line 726, in install
    requirement.uninstall(auto_confirm=True)
  File "C:\Program Files\Python35\lib\site-packages\pip\req\req_install.py", line 746, in uninstall
    paths_to_remove.remove(auto_confirm)
  File "C:\Program Files\Python35\lib\site-packages\pip\req\req_uninstall.py", line 115, in remove
    renames(path, new_path)
  File "C:\Program Files\Python35\lib\site-packages\pip\utils\__init__.py", line 267, in renames
    shutil.move(old, new)
  File "C:\Program Files\Python35\lib\shutil.py", line 553, in move
    os.unlink(src)
PermissionError: [WinError 5] Access denied: 'c:\\program files\\python35\\lib\\site-packages\\pip-8.1.1.dist-info\\description.rst'
You are using pip version 8.1.1, however version 8.1.2 is available.
You should consider upgrading via the 'python -m pip install --upgrade pip' command.