Change Composer hasPackage to public

[buihanh2304]

This method is not used in Composer class, and cannot access from outside.
So, I change it's visibility to public.

[buismaarten]

May be a breaking change when someone is using the method in their application.

[buihanh2304]

@buismaarten How can they use the method without create a new class extends Illuminate\Support\Composer, and then call to the method in that class?

[rodrigopedra]

How can they use the method without create a new class extends Illuminate\Support\Composer, and then call to the method in that class?

That is how.

Also, if, for some reason, they are overriding that method, changing its visibility from protected to public would make their subclass crash.

I agree that is very unlikely, and would be a very niche use case. But with the new year approaching, and thus a new Laravel version approaching, I guess it is safer to send this PR to master instead.

[buihanh2304]

@rodrigopedra

I understood. I will change target branch to master.