Added draft retailcustomer.xsd schema
Merge pull request #188 from MartyBurns/master

Added draft retailcustomer.xsd schema
Issue 190: https://github.com/energyos/OpenESPI-Common-java/issues/190
Modified "bearer" "Bearer"
@XmlElement for appropriate attributes + expires_in -> expires_at
added bias of current time to the value of expiresIn attribute to
accomodate the semantics of expires at.
Lowercased Bearer b/f the OAuth Level test within TokenType.
Corrected "bearer" -> "Bearer" fix
Updated seed files ref:
https://github.com/energyos/OpenESPI-Common-java/issues/130
Made Authorization.third_party @XmlTransient ref:
  https://github.com/energyos/OpenESPI-Common-java/issues/194