More CSS simplification

Edit domain names, updates credentials and virtuals
Model domain tests for length and valid characters

app/views/domains/edit.html.erb

@@ -1,3 +1,5 @@
+<div class="domain">
+
 <h1>Editing domain</h1>
 
 <%= render "form", domain: @domain %>
@@ -5,6 +7,8 @@
 <br>
 
 <div>
-  <%= link_to "Show this domain", @domain %> |
-  <%= link_to "Back to domains", domains_path %>
+  <%= link_to "Back", @domain %> |
+  <%= link_to "Home", domains_path %>
+</div>
+
 </div>