Bump @slack/client from 3.14.2 to 4.3.1 in /back-end

[dependabot-preview]

Bumps @slack/client from 3.14.2 to 4.3.1.

Release notes

Sourced from @slack/client's releases.

v4.3.1

• Fixes an issue where RTMClient would crash after its connection was interrupted because upon reconnection the connection monitoring code would improperly handle new messages as pongs. (#578) - thanks aoberoi.

v4.3.0

• Adds new permissions method named aliases to WebClient: apps.permissions.resources.list and
  apps.permissions.scopes.list (#568) - thanks ggruiz
• Fixes an issue where an RTMClient instance throws errors while trying to reconnect after a connection interuption
  (#560) - thanks aoberoi
• Fixes issue where rate-limit handling in WebClient was not triggering, and adds tests (#570, #573) - thanks ggruiz
• Adds missing IncomingWebhookResult type to exports (#562) - thanks mledom
• Changes options argument of RTMClient#start() to be optional as it was intended (#567) - thanks christophehurpeau

v4.2.2

• Adds the notify_on_cancel field to the Dialog type definition (#541) - thanks DominikPalo
• Adds AttachmentAction type definition to express the type of the action property of MessageAttachment. (#543, #551) - thanks brianeletype, DominikPalo
• Adds the SelectOption type defintion and related properties to the Dialog type definition. (#549) - thanks DominikPalo
• Fixes the missing scopes property in WebClient responses. (#554) - thanks aoberoi
• Fixes an issue in RTMClient where websocket errors in the connecting:authenticated state would cause the program
  to crash. (#555) thanks aoberoi
• Fixes an issue where KeepAlive would monitor the RTM connection while the websocket was not ready after a
  reconnection. (#555) thanks aoberoi
• Uses the "files" key in package.json to implement a whitelist of files that are packed for npm publish.

v4.2.0

• Allows mrkdwn_in and callback_id fields in message attachments for formatting on attachment fields (#528) - thanks DominikPalo
• Fixes optionality of validate argument for channels.join method (#530) - thanks DominikPalo
• Adds the users.conversations method (#532) - thanks DominikPalo
• Fixes overwriting of default parameters after send() call (#535) - thanks franckbrignoli
• Fixes and adds logging for unexpected websocket close in StateMachine (#537) - thanks shanedewael

v4.1.0

• IncomingWebhook.send() works with both callbacks and Promises (#508) - thanks clavin
• Completes type defintions for all WebClient method arguments (#512) - thanks clavin
• Allows files.upload to work with Buffers (in addition to ReadableStreams) (#500) - thanks KharitonOff
• Allows any WebClient methods argument to work with binary types (#519) - thanks clavin and aoberoi
• Fails when WebClient.apiCall() options don't look like the right type (#522) - thanks aoberoi
• Fixes TypeScript compile errors in node >=6 <=8 related to callbackify (#518) - thanks aoberoi
• Fixes mismatched parenthesis in RTMClient usage example documentation (#511) - thanks parthsr
• Adds examples directory back to the repository (#520) - thanks aoberoi

v4.0.1

• Fixes crash in projects where "name" or "version" were not defined in the package.json file (#478) - thanks wilhelmklopp clavin aoberoi
• Fixes IncomingWebhook.send() to parse the response as text instead of JSON (#477) - thanks aoberoi
• Allows IncomingWebhook to be initialized without defaults (#479) - thanks aoberoi
• Allows WebClient to be initialized without a token in TypeScript (#482) - thanks aoberoi
• Allows unspecificed arguments to be used with WebClient method aliases and apiCall() (#484) - thanks clavin
• Exports method argument types as top level exports in the type declarations (#483) - thanks aoberoi
• Fixes inaccurate property type for as_user in ChatPostMessageArguments (#475) - thanks harveyr
• Improves the OAuthAccessArguments and OAuthTokenArguments types (#481) - thanks aoberoi

... (truncated)

Commits

• 5f8abc9 v4.3.1
• 3c8789a Merge pull request #578 from aoberoi/keepalive-inconsistency-issues
• 265aa97 upgrade ws, stop monitoring on recommend reconnect
• 5b4f91b add some logging
• af9b713 improve jsdoc with argument descriptions (linter complained)
• 22dfc6f recommendReconnect is not optional
• 1f49016 KeepAlive: adds handling for cases when monitoring may be stopped before the
• 008402b Merge pull request #574 from slackapi/rel-v4.3.0
• 4b50d20 v4.3.0
• 24488bb Merge pull request #573 from ggruiz/master
• Additional commits viewable in compare view

Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting @dependabot rebase.

---

Dependabot commands and options

You can trigger Dependabot actions by commenting on this PR:

• @dependabot rebase will rebase this PR
• @dependabot merge will merge this PR after your CI passes on it
• @dependabot ignore this [patch|minor|major] version will close this PR and stop Dependabot creating any more for this minor/major version (unless you reopen the PR or upgrade to it yourself)
• @dependabot ignore this dependency will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself)
• @dependabot use these labels will set the current labels as the default for future PRs for this repo and language
• @dependabot use these reviewers will set the current reviewers as the default for future PRs for this repo and language
• @dependabot use these assignees will set the current assignees as the default for future PRs for this repo and language
• @dependabot badge me will comment on this PR with code to add a "Dependabot enabled" badge to your readme

Additionally, you can set the following in your Dependabot dashboard:

• Update frequency (including time of day and day of week)
• Automerge options (never/patch/minor, and dev/runtime dependencies)
• Pull request limits (per update run and/or open at any time)
• Out-of-range updates (receive only lockfile updates, if desired)
• Security updates (receive only security updates, if desired)

Finally, you can contact us by mentioning @dependabot.