delete (id, index) {
    return new Promise((resolve, reject) => {
      const options = {
        url: `api/history/${id}`,
        method: 'DELETE',
        params: { index }
      };

      Vue.axios(options)
        .then((response) => {
          resolve(response);
        }, (error) => {
          reject(error);
        });
    });
  }
Deletes a history item
@param {Object} id The id of the history item to delete
@param {Object} index The es index of the history item to delete
@returns {Promise} Promise A promise object that signals the completion
                           or rejection of the request.