Don't use <center> for twitter embeds

_css/react.scss

@@ -744,3 +744,9 @@ p code {
     float: right;
   }
 }
+
+// Twitter embeds
+div[data-twttr-id] {
+  margin: auto;
+  display: table;
+}

_posts/2014-01-06-community-roundup-14.md

@@ -89,4 +89,4 @@ React is often compared with Angular. [Pete Hunt](http://skulbuny.com/2013/10/31
 
 ## Random Tweet
 
-<center><blockquote class="twitter-tweet" lang="en"><p>Really intrigued by React.js. I&#39;ve looked at all JS frameworks, and excepting <a href="https://twitter.com/serenadejs">@serenadejs</a> this is the first one which makes sense to me.</p>&mdash; Jonas Nicklas (@jonicklas) <a href="https://twitter.com/jonicklas/statuses/412640708755869696">December 16, 2013</a></blockquote></center>
+<div><blockquote class="twitter-tweet" lang="en"><p>Really intrigued by React.js. I&#39;ve looked at all JS frameworks, and excepting <a href="https://twitter.com/serenadejs">@serenadejs</a> this is the first one which makes sense to me.</p>&mdash; Jonas Nicklas (@jonicklas) <a href="https://twitter.com/jonicklas/statuses/412640708755869696">December 16, 2013</a></blockquote></div>

_posts/2014-02-05-community-roundup-15.md

@@ -123,4 +123,4 @@ Adam Solove ([@asolove](https://twitter.com/asolove/)) [dives a little deeper in
 ## Not-so-random Tweet
 
 
-<center><blockquote class="twitter-tweet" lang="en"><p>[@swannodette](https://twitter.com/swannodette) No thank you! It's honestly a bit weird because Om is exactly what I didn't know I wanted for doing functional UI work.</p>&mdash; Adam Solove (@asolove) <a href="https://twitter.com/asolove/status/420294067637858304">January 6, 2014</a></blockquote></center>
+<div><blockquote class="twitter-tweet" lang="en"><p>[@swannodette](https://twitter.com/swannodette) No thank you! It's honestly a bit weird because Om is exactly what I didn't know I wanted for doing functional UI work.</p>&mdash; Adam Solove (@asolove) <a href="https://twitter.com/asolove/status/420294067637858304">January 6, 2014</a></blockquote></div>

support.md

@@ -22,4 +22,4 @@ Many developers and users idle on Freenode.net's IRC network in **[#reactjs on f
 
 [**#reactjs** hash tag on Twitter](https://twitter.com/search?q=%23reactjs) is used to keep up with the latest React news.
 
-<center><a class="twitter-timeline" data-dnt="true" data-chrome="nofooter noheader transparent" href="https://twitter.com/search?q=%23reactjs" data-widget-id="342522405270470656"></a></center>
+<div><a class="twitter-timeline" data-dnt="true" data-chrome="nofooter noheader transparent" href="https://twitter.com/search?q=%23reactjs" data-widget-id="342522405270470656"></a></div>