title: conda not updating pandas
body: <p>I'm trying to update pandas to the latest version (0.23.3) this way:</p>
  
  <pre><code>conda update pandas 
  </code></pre>
  
  <p>I get this message: </p>
  
  <pre><code>All requested packages already installed.
  </code></pre>
  
  <p>But when I check (after restarting Python) using <code>pd.__version__</code> I'm still at 0.23.1 </p>
  
  <p>Am I doing something wrong? Or is Anaconda not current? </p>