NLTK download SSL: Certificate verify failed : <p>I get the following error when trying to install Punkt for nltk:</p>

<pre><code>nltk.download('punkt')    
 [nltk_data] Error loading Punkt: &lt;urlopen error [SSL:
 [nltk_data]     CERTIFICATE_VERIFY_FAILED] certificate verify failed
 [nltk_data]     (_ssl.c:590)&gt;
False
</code></pre>
