Factories implementation

[iyhunko]

• added NeoEloquentFactory class that will be replacing default Laravel's Factory class;
• added NeoFactoryBuilder class that extends default Laravel's Factory class;
• added alias to replace default Illuminate\Database\Eloquent\Factory with a NeoEloquentFactory;
• updated readme.

Now it will be possible to generate Eloquent models(factory(xxx)->make()/ factory(xxx)->create()) via default Laravel's factory() helper function.

Issue details: Previously when we tried to factory(FooModel:class)->create(), we had next issues:

1. Wrong check for Model(abstract class Illuminate\Database\Eloquent\Model) instance that is used in default Illuminate\Database\Eloquent\FactoryBuilder.php thus when we try to create 1 model, it thinks that we try to create a collection of models and we get the each() method does not exists... error.

   /**
    * Create a collection of models and persist them to the database.
    *
    * @param  array  $attributes
    * @return mixed
    */
   public function create(array $attributes = [])
   {
       $results = $this->make($attributes);
   
       if ($results instanceof Model) {
           $this->store(collect([$results]));
       } else {
           $this->store($results);
       }
   
       return $results;
   }

2. Issue in default Illuminate\Database\Eloquent\FactoryBuilder.php (store() method) about non-existing getName() method... Was:

   protected function store($results)
   {
       $results->each(function ($model) {
           if (! isset($this->connection)) {
   
               $model->setConnection($model->newQueryWithoutScopes()->getConnection()->getName());
           }
   
           $model->save();
       });
   }

   will be:

/**
 * Set the connection name on the results and store them.
 *
 * @param  \Illuminate\Support\Collection  $results
 * @return void
 */
protected function store($results)
{
    $results->each(function ($model) {
        if (! isset($this->connection)) {
            $model->setConnection($model->getConnectionName());
        }
        $model->save();
    });
}