Add tap method to ActivityLogger

[Gummibeer]

solves: #462

I've done some more things - because I wasn't able to do a tap() without an activity model instance I've changed all other methods to also work direct on the model. This has a major change, but not breaking, the properties are set on the model in the moment they are called and not just at the end.
I've also cleaned up some things (laravel 5.1 checks, type-hints).
All unit-tests still pass without any change, so I would say that nothing is broken and this just introduces the new feature.

[woliveirac]

Hello,

This feature was missing for me on what i wanted to do, but, now, it's working great.

Thank you !

[dam1r89]

Just an update, we are running this branch on production right now 😉 Waiting to be merged.

[freekmurze]

@Gummibeer looks good 👍
Could you also send a PR to docs with some examples of the new functionality?

[Gummibeer]

@dam1r89 thanks for the feedback. I'm in process to release v3.2.0 - so you will get a new stable release today.

@freekmurze I've already updated the CHANGELOG.md and will add it to the docs after I've released this feature.

[Gummibeer]

release: https://github.com/spatie/laravel-activitylog/releases/tag/3.2.0
packagist: https://packagist.org/packages/spatie/laravel-activitylog#3.2.0
docs:

• https://github.com/spatie/docs.spatie.be/pull/385
• https://docs.spatie.be/laravel-activitylog/v3/basic-usage/logging-activity#tap-activity-before-logged
• https://docs.spatie.be/laravel-activitylog/v3/advanced-usage/logging-model-events#tap-activity-before-logged-from-event