Added a selector for users role in admin cp

app/views/users/_form.html.erb

@@ -13,10 +13,10 @@
     
   <%= f.label :username %>
   <%= f.text_field :username %>
- 
-  <p> 
-   Administrator &nbsp;  <%= f.check_box :is_admin, {checked: @user.admin?} %>
-  </p>
+
+  <br/>
+
+  <%= collection_select(:user, :role_id, Role.all, :id, :name) %> 
 
   <%= f.label :email %>
   <%= f.email_field :email %>