removed symbolset, replaced with fontawesome for settings

cms/static/sass/views/_settings.scss

@@ -328,11 +328,12 @@ body.course.settings {
             @extend .t-action-3;
             font-weight: 600;
 
-            .icon {
+            [class^="icon-"] {
               @extend .t-icon;
               @include font-size(16);
               display: inline-block;
               vertical-align: middle;
+              margin-top: -3px;
             }
           }
         }

cms/templates/settings.html

@@ -92,7 +92,7 @@ from contentstore import utils
 
             <ul class="list-actions">
               <li class="action-item">
-                <a title="Send a note to students via email" href="mailto:someone@domain.com?Subject=Enroll%20in%20${context_course.display_name_with_default}&body=The%20course%20&quot;${context_course.display_name_with_default}&quot;,%20provided%20by%20edX,%20is%20open%20for%20enrollment.%20Please%20navigate%20to%20this%20course%20at%20https:${utils.get_lms_link_for_about_page(course_location)}%20to%20enroll." class="action action-primary"><i class="ss-icon icon ss-symbolicons-standard icon icon-inline icon-announcement">&#x2709;</i> Invite your students</a>
+                <a title="Send a note to students via email" href="mailto:someone@domain.com?Subject=Enroll%20in%20${context_course.display_name_with_default}&body=The%20course%20&quot;${context_course.display_name_with_default}&quot;,%20provided%20by%20edX,%20is%20open%20for%20enrollment.%20Please%20navigate%20to%20this%20course%20at%20https:${utils.get_lms_link_for_about_page(course_location)}%20to%20enroll." class="action action-primary"><i class="icon-envelope-alt icon-inline"></i> Invite your students</a>
               </li>
             </ul>
           </div>