Add reprensation specs for plate.
Add attributes representation to plate spec.
Refactor TubeRackResource to define children_to_stream
Update API version to accept mime-type parameters.

representation=minial : only uuid and action
Merge pull request #29 from maxigit/51550041_design_way_to_handle_content_type_parameter_in_the_api

51550041 design way to handle content type parameter in the api