title: Model association error Rails Admin
body: <p>Getting the following error when trying to intall rails admin... Assuming its a model association error but i cant figure it out..     </p>
  
  <pre><code> /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/activerecord-3.2.3/lib/active_record/inheritance.rb:119:in `compute_type': uninitialized constant Interest::Person (NameError)
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/activerecord-3.2.3/lib/active_record/reflection.rb:172:in `klass'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/rails_admin-0.0.3/lib/rails_admin/adapters/active_record.rb:218:in `association_model_lookup'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/rails_admin-0.0.3/lib/rails_admin/adapters/active_record.rb:63:in `block (2 levels) in associations'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/rails_admin-0.0.3/lib/rails_admin/config/fields/association.rb:59:in `call'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/rails_admin-0.0.3/lib/rails_admin/config/fields/association.rb:59:in `associated_model_config'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/rails_admin-0.0.3/lib/rails_admin/config/fields/association.rb:34:in `block in &lt;class:Association&gt;'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/rails_admin-0.0.3/lib/rails_admin/config/configurable.rb:68:in `instance_eval'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/rails_admin-0.0.3/lib/rails_admin/config/configurable.rb:68:in `block in register_instance_option'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/rails_admin-0.0.3/lib/rails_admin/config/configurable.rb:42:in `block in register_instance_option'
      from (erb):86:in `block (2 levels) in template'
      from (erb):85:in `map'
      from (erb):85:in `block in template'
      from (erb):82:in `map'
      from (erb):82:in `template'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/erb.rb:753:in `eval'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/erb.rb:753:in `result'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/thor-0.14.6/lib/thor/actions/file_manipulation.rb:111:in `block in template'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/thor-0.14.6/lib/thor/actions/create_file.rb:54:in `call'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/thor-0.14.6/lib/thor/actions/create_file.rb:54:in `render'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/thor-0.14.6/lib/thor/actions/create_file.rb:47:in `identical?'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/thor-0.14.6/lib/thor/actions/create_file.rb:73:in `on_conflict_behavior'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/thor-0.14.6/lib/thor/actions/empty_directory.rb:111:in `invoke_with_conflict_check'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/thor-0.14.6/lib/thor/actions/create_file.rb:61:in `invoke!'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/thor-0.14.6/lib/thor/actions.rb:95:in `action'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/thor-0.14.6/lib/thor/actions/create_file.rb:26:in `create_file'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/thor-0.14.6/lib/thor/actions/file_manipulation.rb:110:in `template'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/rails_admin-0.0.3/lib/generators/rails_admin/install_generator.rb:62:in `install'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/thor-0.14.6/lib/thor/task.rb:22:in `run'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/thor-0.14.6/lib/thor/invocation.rb:118:in `invoke_task'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/thor-0.14.6/lib/thor/invocation.rb:124:in `block in invoke_all'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/thor-0.14.6/lib/thor/invocation.rb:124:in `each'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/thor-0.14.6/lib/thor/invocation.rb:124:in `map'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/thor-0.14.6/lib/thor/invocation.rb:124:in `invoke_all'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/thor-0.14.6/lib/thor/group.rb:226:in `dispatch'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/thor-0.14.6/lib/thor/base.rb:389:in `start'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/railties-3.2.3/lib/rails/generators.rb:170:in `invoke'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/railties-3.2.3/lib/rails/commands/generate.rb:12:in `&lt;top (required)&gt;'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:251:in `require'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:251:in `block in require'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:236:in `load_dependency'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/activesupport-3.2.3/lib/active_support/dependencies.rb:251:in `require'
      from /Users/nelsonkeating/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/gems/1.9.1/gems/railties-3.2.3/lib/rails/commands.rb:29:in `&lt;top (required)&gt;'
      from script/rails:6:in `require'
      from script/rails:6:in `&lt;main&gt;'
  </code></pre>
  
  <p>Models</p>
  
  <pre><code>class User &lt; ActiveRecord::Base
    has_many :friends
    has_many :person_interests, :as =&gt; :person
    has_many :interests, :through =&gt; :person_interests
    has_many :user_holidays
    has_many :holidays, :through =&gt; :user_holidays
    has_many :anniversaries
  end
  
  class PersonInterest &lt; ActiveRecord::Base
    attr_accessible :person_id, :person_type, :interest_ids
    belongs_to :interest
    belongs_to :person, :polymorphic =&gt; true
  
  end
  
  class Interest &lt; ActiveRecord::Base
    attr_accessible :name
    has_many :person_interests
    has_many :people, :through =&gt; :person_interests
  
  end
  </code></pre>