title: import airflow -> ImportError: cannot import name version (with Python 2.7)
body: <p>Trying the following code:</p>
  
  <pre class="lang-none prettyprint-override"><code>import airflow
  </code></pre>
  
  <p>I received the following error on python 2.7 in Jupyter Notebook:</p>
  
  <pre class="lang-none prettyprint-override"><code>ImportError                               Traceback (most recent call last)
  &lt;ipython-input-19-6452413eb644&gt; in &lt;module&gt;()
  ----&gt; 1 import airflow
  C:\ProgramData\Anaconda2\lib\site-packages\airflow\__init__.py in &lt;module&gt;()
       26 """
       27 from builtins import object
  ---&gt; 28 from airflow import version
       29 from airflow.utils.log.logging_mixin import LoggingMixin
       30 
  ImportError: cannot import name version
  </code></pre>
  
  <p>I have seen similar issues on the forum, but there were no definitive answers to this issue.</p>