step12 liberatorのイメージをビルドできない。

[yukinakanaka]

liberatorのイメージをビルド中に、エラーが発生する

$ docker build --tag gyuki1029/liberator:0.1 .
Sending build context to Docker daemon   5.12kB
Step 1/7 : FROM ubuntu:16.04
16.04: Pulling from library/ubuntu
8e097b52bfb8: Pull complete 
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Step 4/7 : RUN pip install kubernetes
 ---> Running in f3e762382fea
Collecting kubernetes
  Downloading https://files.pythonhosted.org/packages/60/3f/2fef94fb65e8f94d768356e5fb9be222d18027e6167ccc65e2090917a771/kubernetes-11.0.0.tar.gz (724kB)
Collecting certifi>=14.05.14 (from kubernetes)
  Downloading https://files.pythonhosted.org/packages/5e/c4/6c4fe722df5343c33226f0b4e0bb042e4dc13483228b4718baf286f86d87/certifi-2020.6.20-py2.py3-none-any.whl (156kB)
Collecting six>=1.9.0 (from kubernetes)
  Downloading https://files.pythonhosted.org/packages/ee/ff/48bde5c0f013094d729fe4b0316ba2a24774b3ff1c52d924a8a4cb04078a/six-1.15.0-py2.py3-none-any.whl
Collecting python-dateutil>=2.5.3 (from kubernetes)
  Downloading https://files.pythonhosted.org/packages/d4/70/d60450c3dd48ef87586924207ae8907090de0b306af2bce5d134d78615cb/python_dateutil-2.8.1-py2.py3-none-any.whl (227kB)
Collecting setuptools>=21.0.0 (from kubernetes)
  Downloading https://files.pythonhosted.org/packages/38/cc/db23dbe4efc464c3c0111fedf7d46de8888f05b09488d610f6f8ab6e2544/setuptools-49.6.0.zip (2.2MB)
    Complete output from command python setup.py egg_info:
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "setuptools/__init__.py", line 19, in <module>
        import setuptools.version
      File "setuptools/version.py", line 1, in <module>
        import pkg_resources
      File "pkg_resources/__init__.py", line 1380
        raise SyntaxError(e) from e
                                ^
    SyntaxError: invalid syntax
    
    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-EgwRl7/setuptools/
You are using pip version 8.1.1, however version 20.2.2 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
The command '/bin/sh -c pip install kubernetes' returned a non-zero code: 1