add Line Notify support

[lukedoomer]

LINE is the most popular messenger in Southeast Asian countries like Japan, Korea, Taiwan, etc.

documentation
https://notify-bot.line.me/doc/en/
example
https://engineering.linecorp.com/en/blog/using-line-notify-to-send-messages-to-line-from-the-command-line/

[liiight]

Will do this on next release

[liiight]

Seems like I cannot register a new service to try their API. If you have an existing account I could use for development, that would be great