When opening PR then auto-scan with kiwitcms-bot

[atodorov]

GitHub actions and @kiwitcms-bot is a good way to start automating some code review and sanity testing. For example:

• indicate missing new lines at the end of source code files which is a common mistake.

Once all the machinery is in place this can be extended with arbitrary checks opening the way for what is called "programming with bots" and "testing with bots".

This idea is inline with Kiwi TCMS goal to make testing easier for teams.