email delivery on submitting new question

When a user submits a new question, an email is sent to them confirming their submission with links to share on social media. Example:

```html
<!DOCTYPE html>
<html>
  <head>
    <meta content="text/html; charset=UTF-8" http-equiv="Content-Type" />
  </head>
  <body>
    <h1>Thank you for posting your question to AskThem, Derek</h1>

    <dl>
      <dt>Title</dt>
      <dd>This is my important question!</dd>

      <dt>Topic</dt>
      <dd>Arts and Humanities</dd>

      <dt>To</dt>
      <dd>
        <strong><a href="http://localhost:3000/il/people/ILL000065">Maria Antonia Berrios</a></strong>
        <span>(Representative, District 39, Democratic)</span>
      </dd>

      <dt>Body</dt>
      <dd>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</dd>
    </dl>

    <p>
      <a href="http://localhost:3000/il/questions/52015e6a8e573493fb000002">Here's a permalink to your question</a>, which you can share over email and social media.
    </p>
    <p>
      Remember to circulate your question to reach the signature threshold, and we'll help you push for a public response.
    </p>
    <p>
      For more info about how to gather support for your question, <a href="#">please visit our FAQ</a>.
    </p>
    <p>
        Thank you,
        The AskThem Team
    </p>
  </body>
</html>
```

Content needs review by @davidmooreppf.

@walter, is this spec for the email sufficient?


Closes #19