{% if site.github_username != null %}
<a href="https://github.com/{{site.github_username}}" target="_blank">
  <i class="fa fa-github fa-3x"></i>
</a>
{% endif %}
{% if site.email != null %}
<a href="mailto:{{site.email}}">
  <i class="fa fa-envelope fa-3x"></i>
</a>
{% endif %}
{% if site.facebook_username != null %}
<a href="https://www.facebook.com/{{site.facebook_username}}" target="_blank">
  <i class="fa fa-facebook fa-3x"></i>
</a>
{% endif %}
{% if site.twitter_username != null %}
<a href="https://twitter.com/{{site.twitter_username}}" target="_blank">
  <i class="fa fa-twitter fa-3x"></i>
</a>
{% endif %}
{% if site.linkedin_id != null %}
<a href="https://www.linkedin.com/in/{{site.linkedin_id}}" target="_blank">
  <i class="fa fa-linkedin fa-3x"></i>
</a>
{% endif %}