wellflat

This is a plugin which gives you a small card to show your GitHub user profile summary. You just have to put shortcode.
Features include: 
+ GitHub account name and avatar 
+ recently active repository 
+ frequently used language list sorted by repository’s stargazers count 
+ public repositories and gists count 
+ followers count 
+ total stargazers count
Notice: 
This plugin caches GitHub user profile data into the database (expires 4 hours).

WP GitHub Card

This plugin provides simple GitHub profile summary card.

Pedro Elsner

Drop in the embed code from github between the gist shortcode.
<pre><code>[gist]<script src="http://gist.github.com/447298.js?file=github_gist_wordpress_plugin_test.txt"></script>[/gist]
</code></pre>
or pass the ID and file (optional)
<pre><code>[gist id=447298 file=github_gist_wordpress_plugin_test.txt]
</code></pre>

Gist for Robots WordPress Plugin

Makes embedding Github.com gists SEO friendly and super awesomely easy.

WP GitHub Card vs Gist for Robots WordPress Plugin