picto emission

panikweb_templates/templates/emissions/nav.html

 <nav>
 	<ul class="inline">
 		<li><a href="{% url 'emissions' %}">
-			<span class="icon-bullhorn" ></span>
+			<span class="icon-microphone" ></span>
 			<span class="iconLabel">Emissions</span>
 		</a></li>
 		<li><a href="{% url 'program' %}">