code: function convertAdditionalProperties (data, additionalProperties) {
    if (additionalProperties !== undefined) {
      let val = data
      if (typeof additionalProperties === 'boolean') val = additionalProperties
      if (typeof additionalProperties === 'object' && Object.keys(additionalProperties).length === 0) val = true
      if (typeof additionalProperties === 'object' && Object.keys(additionalProperties).length > 0) {
        const type = additionalProperties.type
        data.properties['//'] = { type: type }
        val = false
      }
      data.additionalProperties = val
    }
    return data
  }
docs: convert additionalProperties from jsonSchema to raml form
  
  @param  {Object} data - current data
  @param  {*} additionalProperties - potential additional properties
  @returns  {Object} raml form