Readded SSN and Gender to Participant Details. Hide all but last 4 of ssn on Show view.

app/views/participants/show.html.erb

@@ -32,6 +32,14 @@
             <th>DOB</th>
             <td><%= @participant.dob.strftime('%B %d, %Y') if @participant.dob.present? %></td>
           </tr>
+          <tr>
+            <th>SSN</th>
+            <td><%= mask_ssn(@participant.ssn) %></td>
+          </tr>
+          <tr>
+            <th>Gender</th>
+            <td><%= @participant.gender %></td>
+          </tr>
         </tbody>
       </table>
     </div>