title: Cannot switch Python with pyenv
body: <p>I would like to use pyenv to switch python2 and python3.</p>
  
  <p>I successfully downloaded python2 and python3 and pyenv with following codes.</p>
  
  <pre><code>brew install pyenv
  
  brew install pyenv-virtualenv
  
  pyenv install 2.7.10
  
  pyenv install 3.5.0
  </code></pre>
  
  <p>However, I cannot switch from python2 to python3..</p>
  
  <pre><code>Soma-Suzuki:~ Soma$ python --version
  Python 2.7.10
  Soma-Suzuki:~ Soma$ pyenv global
  2.7.10
  Soma-Suzuki:~ Soma$ pyenv versions
    system
  * 2.7.10 (set by /Users/Soma/.pyenv/version)
    3.5.0
  Soma-Suzuki:~ Soma$ pyenv global 3.5.0
  Soma-Suzuki:~ Soma$ pyenv global
  3.5.0
  Soma-Suzuki:~ Soma$ pyenv versions
    system
    2.7.10
  * 3.5.0 (set by /Users/Soma/.pyenv/version)
  Soma-Suzuki:~ Soma$ python --version
  Python 2.7.10
  Soma-Suzuki:~ Soma$ 
  </code></pre>
  
  <p>I do not understand why this happens.</p>
  
  <p>For your information.
  My python is in this directory.</p>
  
  <pre><code>Soma-Suzuki:~ Soma$ which python
  /usr/bin/python
  </code></pre>
  
  <p>Thank you in advance.</p>