Adding override of auto generated nickname

 Swagger has a nickname filed specified in the 1.2 standard. It is used
to generate an alternate name for code generators to use for that api.
This patch provides a way to override the generated nickname with one
specified in the grape documentation.

    Example:
          desc(
            'Get all the cloud profiles in the system',
            :nickname => 'getAllCloudProfiles',
          )
Merge pull request #100 from maginatics/FW-Port

Should be able to override the generated nicknames