Use hooks for on_booted event. (#1160)
Use hooks for on_booted event. (#1160)

* Use hooks for on_booted event.

Callbacks were introduced after Events#on_booted.

https://github.com/puma/puma/commit/b24920d3eda7a7f60da99c006f0d4f082b69d752#diff-af46a0af8a5e391324bbe812613b44a8R25

* Fix typo.

eileencodes/puma,unleashed/puma,unleashed/puma,looker/puma,respire/puma,looker/puma,puma/puma,eileencodes/puma,respire/puma,puma/puma,unleashed/puma,eileencodes/puma,looker/puma,looker/puma,eileencodes/puma,puma/puma,unleashed/puma,respire/puma,puma/puma,respire/puma