title: SendGrid -> TypeError: cannot concatenate 'str' and 'NoneType' objects
body: <p>I'm fairly new to this, but I've basically copied the example straight from github and gotten the error: <code>TypeError: cannot concatenate 'str' and 'NoneType' objects</code>. I believe I'm setting the environment variable correctly, just not really sure what I'm missing. Thanks for the help.</p>
  
  <pre><code>import sendgrid
  import os
  
  sg = sendgrid.SendGridClient(os.environ.get('SENDGRID_API_KEY'))
  
  message = sendgrid.Mail()
  message.add_to('Recip &lt;redacted@gmail.com&gt;')
  message.set_subject('Example')
  message.set_html('Body')
  message.set_text('Body')
  message.set_from('Sender &lt;redacted@gmail.com&gt;')
  status, msg = sg.send(message)
  print(status, msg)
  </code></pre>