Having looked around for CSS emoji integration I could only find ones that were image based. So I've but together a version using Unicode in a font awesome inspired way:
<i class="emoji emoji-grinning-face" aria-hidden="true"></i>With bower:
$ bower install css-emoji --save
Or just download the zip and include the CSS or SASS in your project.
Reference can be found in example/example.html (better docs to follow!).
Note: While all V3 emojis are included, some may not be supported by a browser. They have been included for completeness in the hope vendors honour them further down the line.