Changes to POST /games

removed the request property element

removed the request property id

removed the request property value

removed the optional property element from the response with the 201 status

removed the optional property value from the response with the 201 status

request body became optional

added the optional property started_on to the response with the 201 status

added the new required request property element

added the new required request property id

added the new required request property value

request body became required

removed the optional property started_on from the response with the 201 status

added the optional property element to the response with the 201 status

added the optional property value to the response with the 201 status