added username of user who answered the question

app/assets/stylesheets/base.css.scss

@@ -31,6 +31,13 @@ body {
   width: 32px;
 }
 
+.img-answerbox-small {
+  min-height: 20px;
+  min-width: 20px;
+  height: 20px;
+  width: 20px;
+}
+
 .answerbox-question-text, .answerbox-question-user {
   margin-bottom: 0px;
 }

app/views/shared/_answerbox.html.haml

@@ -10,6 +10,11 @@
   .panel-body
     %p= a.content
     %br/
+    %p.text-muted
+      Answered by
+        %a{href: show_user_profile_path(a.user.screen_name)}
+          %img.img-rounded.img-answerbox-small{src: gravatar_url(a.user)}
+          %span= a.user.screen_name
     - if privileged? a.user
       %button.btn.btn-danger{name: 'ab-destroy', 'data-a-id' => a.id}
         Delete