Get default attributes for schemas and hydrators from model fillable attribute

[pedroluislopez]

This implementation uses fillable attributes from eloquent models to avoid repetition of these attributes declaration in the schema and hydrator classes (by default, if attributes are declared in schema/hydrator class, these are used).

[lindyhopchris]

@pedroluislopez

thanks for this PR and the feature suggestion. I've merged with develop but won't be tagging immediately as I need to see what other changes I might include in the next release.

If you want to use now, set "minimum-stability": "dev" in your composer.json and then:

$ composer require cloudcreativity/laravel-json-api:^0.7

That will pull in the develop branch (which will eventually become 0.7.0)

[pedroluislopez]

@lindyhopchris Ok, thanks.

[lindyhopchris]

This has been released as v0.7.0