Fix pagination sample code
Fix pagination sample code

- users.list returns "members" object rather than "users"
- response_metadata doesn't return "cursor" key, but "next_cursor"

slackhq/node-slack-sdk,slackhq/node-slack-client,slackapi/node-slack-sdk,slackapi/node-slack-sdk,slackapi/node-slack-sdk,slackapi/node-slack-sdk