Using the LookupKey base class can result in the following deprecation warning from Rails:

2.0.0-p353 :001 > LookupKey.all
  LookupKey Load (3.6ms)  SELECT "lookup_keys".* FROM "lookup_keys" ORDER BY lookup_keys.key
2015-09-16T14:23:26 [app] [W] DEPRECATION WARNING: It looks like something (probably a gem/plugin) is overriding the ActiveRecord::Base.inherited method. It is important that this hook executes so that your models are set up correctly. A workaround has been added to stop this causing an error in 3.2, but future versions will simply not work if the hook is overridden. If you are using Kaminari, please upgrade as it is known to have had this problem.
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 | The following may help track down the problem: ["/home/dcleal/code/foreman/foreman/app/models/lookup_keys/lookup_key.rb", 34]
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 |  (called from irb_binding at (irb):1)

It appears that the LookupKey.inherited method isn't calling "super".

This causes logging when used on develop as shown above, or with the PR for #9981.