* Added tests for MS Teams.
* Added tests for Dingtalk.
* Added tests for Telegram.
* Added tests for Feishu.
* Added tests for Discord.
* Added tests for closed issue and pullrequest comment.
* Added tests for Matrix.
* Trim all spaces.
* Added tests for Slack.
* Added JSONPayload tests.
* Added general tests.
* Replaced duplicated code.
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
