Prevent Circular Structure error for slack service

[eason9487]

Slack will use JSON.stringify(value) to handle non-string value,
so it would throw Circular Structure error when value having circular reference.
https://github.com/slackapi/node-slack-sdk/blob/fb4bc6fe62e055581d342b8279350d59325930d3/lib/clients/helpers.js#L30

It throws exception when passing request object from router of Express

node-logger/src/service/slack.js

Line 41 in c583a30

value: logMessageFields[key],

We can avoid it by passing value to a filter function likes:

import { forEach, isObject } from 'lodash';

function removeCircularStructure(object, set = new Set(), nextObject = {}) {
  forEach(object, (value, key) => {
    if (isObject(value)) {
      if (set.has(value)) {
        return;
      }

      set.add(value);
      nextObject[key] = removeCircularStructure(value, set);
      return;
    }

    nextObject[key] = value;
  });

  return nextObject;
}

Or do something else to prevent this error.