An Omniauth 1.0 Strategy for yahoo

For more information see the following:

• https://github.com/intridea/omniauth/wiki/List-of-Strategies

Release notes:

• Version 0.0.4

  • Added skip_info? patch from mkdynamic

• Version 0.0.3

  • Added primary email as per famoseagle

• Version 0.0.1

  • First cut