app/views/subscriptions/index.html.erb
<h1>Listing Subscriptions</h1>
<table>
<thead>
<tr>
<th>User</th>
<th>Subscribable</th>
<th colspan="3"></th>
</tr>
</thead>
<tbody>
<% @subscriptions.each do |subscription| %>
<tr>
<td><%= subscription.user.email %></td>
<td><%= subscription.subscribable.display_name %></td>
<td><%= link_to 'Destroy', subscription, method: :delete, data: { confirm: 'Are you sure?' } %></td>
</tr>
<% end %>
</tbody>
</table>
<br>
<%= link_to 'New Subscription', new_subscription_path %> | <%= link_to "Back", user_path(current_user) %>