Louis | Add sign in / sign out link to header

app/views/layouts/_navbar.html.erb

@@ -13,6 +13,12 @@
     <ul class="nav navbar-nav navbar-right">
       <li><%= link_to "Bikes", bikes_path %></li>
       <li><%= link_to "Clients", clients_path %></li>
+      <li><%= if current_user
+                link_to "Sign Out", destroy_user_session_path, method: :delete
+              else
+                link_to "Sign In", new_user_session_path
+              end %></li>
+
     </ul>
   </div>
 </nav>