apipie - :undef is not a valid apipie param type

it makes katello_api, hammer_cli_katello, and hammer-cli blow up with:

```
$ bundle exec hammer -v
[ INFO 2014-02-05 14:55:17 Init] Initialization of Hammer CLI (0.0.18) has started...
[ INFO 2014-02-05 14:55:17 Init] Configuration from the file /home/adprice/.foreman/cli_config.yml has been loaded
[ INFO 2014-02-05 14:55:18 Modules] Extension module hammer_cli_foreman (0.0.18) loaded
[ INFO 2014-02-05 14:55:18 HammerCLI::MainCommand] subcommand organization (HammerCLIForeman::Organization) was removed.
[ INFO 2014-02-05 14:55:18 HammerCLI::MainCommand] subcommand organization (HammerCLIKatello::Organization) was created.
file loaded
[ERROR 2014-02-05 14:55:18 Modules] Error while loading module hammer_cli_katello
[ERROR 2014-02-05 14:55:18 Modules] <NoMethodError> undefined method `include?' for nil:NilClass
        /home/adprice/hammer-cli/lib/hammer_cli/apipie/options.rb:92:in `option_opts'
        /home/adprice/hammer-cli/lib/hammer_cli/apipie/options.rb:69:in `create_option'
        /home/adprice/hammer-cli/lib/hammer_cli/apipie/options.rb:59:in `block in options_for_params'
        /home/adprice/hammer-cli/lib/hammer_cli/apipie/options.rb:54:in `each'
        /home/adprice/hammer-cli/lib/hammer_cli/apipie/options.rb:54:in `options_for_params'
        /home/adprice/hammer-cli/lib/hammer_cli/apipie/options.rb:47:in `apipie_options'
        /home/adprice/hammer-cli-katello/lib/hammer_cli_katello/repository.rb:13:in `<class:CreateCommand>'
        /home/adprice/hammer-cli-katello/lib/hammer_cli_katello/repository.rb:7:in `<class:Repository>'
        /home/adprice/hammer-cli-katello/lib/hammer_cli_katello/repository.rb:4:in `<module:HammerCLIKatello>'
        /home/adprice/hammer-cli-katello/lib/hammer_cli_katello/repository.rb:2:in `<top (required)>'
        /home/adprice/hammer-cli-katello/lib/hammer_cli_katello.rb:16:in `require'
        /home/adprice/hammer-cli-katello/lib/hammer_cli_katello.rb:16:in `block in <module:HammerCLIKatello>'
        /home/adprice/hammer-cli-katello/lib/hammer_cli_katello.rb:15:in `each'
        /home/adprice/hammer-cli-katello/lib/hammer_cli_katello.rb:15:in `<module:HammerCLIKatello>'
        /home/adprice/hammer-cli-katello/lib/hammer_cli_katello.rb:9:in `<top (required)>'
        /home/adprice/hammer-cli/lib/hammer_cli/modules.rb:47:in `require'
        /home/adprice/hammer-cli/lib/hammer_cli/modules.rb:47:in `require_module'
        /home/adprice/hammer-cli/lib/hammer_cli/modules.rb:24:in `load!'
        /home/adprice/hammer-cli/lib/hammer_cli/modules.rb:41:in `load'
        /home/adprice/hammer-cli/lib/hammer_cli/modules.rb:52:in `block in load_all'
        /home/adprice/hammer-cli/lib/hammer_cli/modules.rb:51:in `each'
        /home/adprice/hammer-cli/lib/hammer_cli/modules.rb:51:in `load_all'
        /home/adprice/hammer-cli/bin/hammer:54:in `<top (required)>'
        /home/adprice/.rvm/gems/ruby-1.9.3-p484@hammer/bin/hammer:23:in `load'
        /home/adprice/.rvm/gems/ruby-1.9.3-p484@hammer/bin/hammer:23:in `<main>'
Warning: An error occured while loading module hammer_cli_katello
```

which is not helpful or indicative of the actual problem.
Merge pull request #3669 from komidore64/undef-dont-use

apipie - :undef is not a valid apipie param type