Swagger nickname strategy

Currently, the swagger nickname strategy can produce undesired results.  For instance, if I have an API POST path of `/api/pet/create`, the swagger nickname/api method will be generated as `post_pet-create`.  

I have introduced a new configuration option, `nickname_naming_strategy`, which will allow users to specify whether they would prefer camel-cased nicknames (to generate camel-cased swagger methods).  The nickname would be `postPetCreate`.  

The default method is `normalize` to prevent any BC breaks.