title: rails_admin breaks everything, uninitialized constant Admin (NameError)
body: <h1>What I try to archieve</h1>
  <p>I am writing a rails app that is mostly CRUD. I want to have an admin interface so that non-programmers should be able to control the content. I decided to go with the ready-made library <a href="https://github.com/sferik/rails_admin" rel="nofollow noreferrer">rails admin</a>, because it seems to be the one that offers the most of convention &gt; configuration.</p>
  <h1>What goes wrong</h1>
  <p>Well, mostly everything.</p>
  <p>Everytime I run a command that uses the rails configuration (it seems) it halts and gives me a long error. The errors I get in my shells <a href="http://pastie.org/private/qsccdnb8m0pycv2i2vtq2a" rel="nofollow noreferrer">are posted here</a> if you can understand it better than I do.</p>
  <p>If I do another rails command, such as <code>rails g model Admin</code> it fails in the same manner, complaining <code>uninitialized constant Admin (NameError)</code>.</p>
  <p><a href="http://pastie.org/private/0khunhucfsdwpdcw7gggog" rel="nofollow noreferrer">This is my Gemfile</a>.</p>
  <h1>How it got this bad</h1>
  <p>I was strolling along, whistling and having a jolly time. Created a ruby application, installed Devise and set up the User class with it, scaffolded a few CRUD MVC's, made a few custom controllers-views. I know that the gem 'will_paginate' is in conflict with 'rails_admin', so I removed it from my gemfile and instead went with 'kaminari'.</p>
  <h1>Who I suspect</h1>
  <p><a href="https://github.com/sferik" rel="nofollow noreferrer">Erik</a>. No, I'm sure he's great. But rails_admin obviously did not play nice with my app. I suspect this has something to do with me not creating an 'Admin' model before installing the gem. But I can't fix it now, since I get theese errors (and I get errors even if I remove rails_admin from the gemfile, do a <code>bundle</code> and then try to <code>rails g</code>).</p>