Track reopened PRs

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Example:

<div class="alert issues_reopened"><div class="body"><!-- pull_request -->
<svg aria-label="Pull request" class="octicon octicon-git-pull-request dashboard-event-icon" height="32" role="img" version="1.1" viewBox="0 0 12 16" width="24"><path fill-rule="evenodd" d="M11 11.28V5c-.03-.78-.34-1.47-.94-2.06C9.46 2.35 8.78 2.03 8 2H7V0L4 3l3 3V4h1c.27.02.48.11.69.31.21.2.3.42.31.69v6.28A1.993 1.993 0 0 0 10 15a1.993 1.993 0 0 0 1-3.72zm-1 2.92c-.66 0-1.2-.55-1.2-1.2 0-.65.55-1.2 1.2-1.2.65 0 1.2.55 1.2 1.2 0 .65-.55 1.2-1.2 1.2zM4 3c0-1.11-.89-2-2-2a1.993 1.993 0 0 0-1 3.72v6.56A1.993 1.993 0 0 0 2 15a1.993 1.993 0 0 0 1-3.72V4.72c.59-.34 1-.98 1-1.72zm-.8 10c0 .66-.55 1.2-1.2 1.2-.65 0-1.2-.55-1.2-1.2 0-.65.55-1.2 1.2-1.2.65 0 1.2.55 1.2 1.2zM2 4.2C1.34 4.2.8 3.65.8 3c0-.65.55-1.2 1.2-1.2.65 0 1.2.55 1.2 1.2 0 .65-.55 1.2-1.2 1.2z"></path></svg>

<div class="time">
  <relative-time datetime="2017-06-05T20:39:00Z">Jun 6, 2017</relative-time>
</div>

<div class="title">
  <a href="/sindresorhus" data-ga-click="News feed, event click, Event click type:PullRequestEvent target:actor">sindresorhus</a> reopened pull request <a href="/sindresorhus/refined-github/pull/467" data-ga-click="News feed, event click, Event click type:PullRequestEvent target:pull">sindresorhus/refined-github#467</a>
</div>

<div class="details">
  <a href="/sindresorhus"><img alt="@sindresorhus" class="gravatar" height="30" src="https://avatars2.githubusercontent.com/u/170270?v=3&amp;s=60" width="30"></a>
  <div class="message">
    <blockquote>Correctly linkify repeating URLs on the same line</blockquote>
      <div class="pull-info">
        <svg aria-hidden="true" class="octicon octicon-git-commit" height="16" version="1.1" viewBox="0 0 14 16" width="14"><path fill-rule="evenodd" d="M10.86 7c-.45-1.72-2-3-3.86-3-1.86 0-3.41 1.28-3.86 3H0v2h3.14c.45 1.72 2 3 3.86 3 1.86 0 3.41-1.28 3.86-3H14V7h-3.14zM7 10.2c-1.22 0-2.2-.98-2.2-2.2 0-1.22.98-2.2 2.2-2.2 1.22 0 2.2.98 2.2 2.2 0 1.22-.98 2.2-2.2 2.2z"></path></svg>
        <em>1</em> commit with
        <em>3</em> additions and
        <em>5</em> deletions
      </div>
  </div>
</div>
</div></div>