03 pipのエラー「pkg_resources.DistributionNotFound: pip==1.5.4」

pipでインストールしようとするとエラーが出る

# pip install cloudmonkey
Traceback (most recent call last):
  File "/usr/bin/pip", line 5, in <module>
    from pkg_resources import load_entry_point
  File "build/bdist.linux-x86_64/egg/pkg_resources.py", line 2749, in <module>
  File "build/bdist.linux-x86_64/egg/pkg_resources.py", line 444, in _build_master
  File "build/bdist.linux-x86_64/egg/pkg_resources.py", line 725, in require
  File "build/bdist.linux-x86_64/egg/pkg_resources.py", line 628, in resolve
pkg_resources.DistributionNotFound: pip==1.5.4

# easy_install --upgrade pip