Allow models to require approval only when needed

[mankowitz]

For my use case, I had many crud operations already defined for my models, and only wanted approval in certain circumstances. With this PR, approval can be turned off and on as needed by attaching the trait MayBeApproved.

namespace App;

use \Illuminate\Database\Eloquent\Model;
use Cjmellor\Approval\Concerns\MayBeApproved;

class Site extends Model 
{
    use MayBeApproved;
}

Now, in normal use, if I want to update a particular attribute of a site, it works normally (return true). When I execute the command requireApproval() and then update the site, it return false and inserts the Morph into the approvals table. I can turn the requirement off again with requireApproval(false)

>>> Site::find(109)->update(['zip'=>rand()]);
[!] Aliasing 'Site' to 'App\Site' for this Tinker session.
=> true

>>> Site::requireApproval()
=> null

>>> Site::find(109)->update(['zip'=>rand()]);
=> false

>>> Site::requireApproval(false)
=> null

>>> Site::find(109)->update(['zip'=>rand()]);
=> true

In addition, I can also commit changes as follows

Site::find(109)->approvals()->first()->commit(); // commit the first approval
Site::find(109)->approvals->each->commit()    // commit all approvals

[cjmellor]

Hi,

Thanks for the PR.

I am not going to be approving it as it is not achieving anything I want for this package.

My suggestion is to fork this repo and use it in your project as what you're after is unique just to you.

Thanks.