I would also rename github.php to a .php so it's not guessable by attackers, for example using textmechanic.com/text-tools/random... to come up with a filename.
It's quite sad that I could not easily find a gist with a recommended example.
For further actions, you may consider blocking this person and/or reporting abuse
We're a place where coders share, stay up-to-date and grow their careers.
The PHP code for the GitHub webhook is insecure. Anyone can all it any number of times and bring down your site.
After you've setup the webhook please read developer.github.com/webhooks/secu... and secure your webhook with a secret!
I would also rename github.php to a .php so it's not guessable by attackers, for example using textmechanic.com/text-tools/random... to come up with a filename.
It's quite sad that I could not easily find a gist with a recommended example.