Convert remaining heading titles to use h1

This makes them consistent with all the other pages that use h1
in the `content_for :heading` sections

app/views/traces/edit.html.erb

@@ -1,5 +1,5 @@
 <% content_for :heading do %>
-  <h2><%= t ".heading", :name => @trace.name %></h2>
+  <h1><%= t ".heading", :name => @trace.name %></h1>
 <% end %>
 
 <img src="<%= url_for :controller => "traces", :action => "picture", :id => @trace.id, :display_name => @trace.user.display_name %>">