MacOS (El Capitan) でのaws-cliアップデート

## これは？

MacOS (El Capitan) でaws-cliをアップデートするときのコマンドです。

## El Capitanアップデートの実行

普通にupdateするとエラーになるので、以下のコマンドでupdateします。

```
sudo pip install awscli --upgrade --ignore-installed six
```

## 普通に実行すると、以下のエラーに遭遇します


```bash

[~/bohelabo 19:06:42]$ sudo pip install -U awscli
Password:
The directory '/Users/bohebohechan/Library/Caches/pip/http' or its parent directory is not owned by the current user and the cache has been disabled. Please check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag.
The directory '/Users/bohebohechan/Library/Caches/pip' or its parent directory is not owned by the current user and caching wheels has been disabled. check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag.
Collecting awscli
  Downloading awscli-1.10.19-py2.py3-none-any.whl (919kB)
    100% |████████████████████████████████| 921kB 634kB/s
Requirement already up-to-date: rsa<=3.3.0,>=3.1.2 in /Library/Python/2.7/site-packages (from awscli)
Requirement already up-to-date: s3transfer==0.0.1 in /Library/Python/2.7/site-packages (from awscli)
Requirement already up-to-date: colorama<=0.3.3,>=0.2.5 in /Library/Python/2.7/site-packages (from awscli)
Collecting botocore==1.4.10 (from awscli)
  Downloading botocore-1.4.10-py2.py3-none-any.whl (2.3MB)
    100% |████████████████████████████████| 2.3MB 249kB/s
Requirement already up-to-date: docutils>=0.10 in /Library/Python/2.7/site-packages (from awscli)
Requirement already up-to-date: pyasn1>=0.1.3 in /Library/Python/2.7/site-packages (from rsa<=3.3.0,>=3.1.2->awscli)
Requirement already up-to-date: futures<4.0.0,>=2.2.0 in /Library/Python/2.7/site-packages (from s3transfer==0.0.1->awscli)
Requirement already up-to-date: jmespath<1.0.0,>=0.7.1 in /Library/Python/2.7/site-packages (from botocore==1.4.10->awscli)
Collecting python-dateutil<3.0.0,>=2.1 (from botocore==1.4.10->awscli)
  Downloading python_dateutil-2.5.2-py2.py3-none-any.whl (201kB)
    100% |████████████████████████████████| 204kB 2.6MB/s
Collecting six>=1.5 (from python-dateutil<3.0.0,>=2.1->botocore==1.4.10->awscli)
  Downloading six-1.10.0-py2.py3-none-any.whl
Installing collected packages: six, python-dateutil, botocore, awscli
  Found existing installation: six 1.4.1
    DEPRECATION: Uninstalling a distutils installed project (six) has been deprecated and will be removed in a future version. This is due to the fact that uninstalling a distutils project will only partially uninstall the project.
    Uninstalling six-1.4.1:
Exception:
Traceback (most recent call last):
  File "/Library/Python/2.7/site-packages/pip-8.0.2-py2.7.egg/pip/basecommand.py", line 209, in main
    status = self.run(options, args)
  File "/Library/Python/2.7/site-packages/pip-8.0.2-py2.7.egg/pip/commands/install.py", line 317, in run
    prefix=options.prefix_path,
  File "/Library/Python/2.7/site-packages/pip-8.0.2-py2.7.egg/pip/req/req_set.py", line 725, in install
    requirement.uninstall(auto_confirm=True)
  File "/Library/Python/2.7/site-packages/pip-8.0.2-py2.7.egg/pip/req/req_install.py", line 752, in uninstall
    paths_to_remove.remove(auto_confirm)
  File "/Library/Python/2.7/site-packages/pip-8.0.2-py2.7.egg/pip/req/req_uninstall.py", line 115, in remove
    renames(path, new_path)
  File "/Library/Python/2.7/site-packages/pip-8.0.2-py2.7.egg/pip/utils/__init__.py", line 266, in renames
    shutil.move(old, new)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/shutil.py", line 302, in move
    copy2(src, real_dst)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/shutil.py", line 131, in copy2
    copystat(src, dst)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/shutil.py", line 103, in copystat
    os.chflags(dst, st.st_flags)
OSError: [Errno 1] Operation not permitted: '/tmp/pip-EupUTB-uninstall/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/six-1.4.1-py2.7.egg-info'
You are using pip version 8.0.2, however version 8.1.1 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
```