app/views/users/index.html.erb
<%= render '/header.html.erb' %>
<h2>Welcome</h2>
<% if current_user %>
<p>
<%= current_user.name %> ... is great
</p>
<%= link_to "Log-Out", log_out_path, method: :delete %>
<% else%>
<%= link_to "Log-In", log_in_path %>
<%= link_to "Sign-Up", users_new_path %>
<% end %>
<ul>
<% @users.each do |user| %>
<li>
<%= user.name %>
</li>
<% end %>
</ul>