Inuit sync of tax, product accounting, accounts and invoices

app/Models/Invoice.php

@@ -209,6 +209,13 @@ class Invoice extends Model implements IDs
 		return $this->hasMany(PaymentItem::class);
 	}
 
+	public function providers()
+	{
+		return $this->belongsToMany(ProviderOauth::class,'invoice__provider')
+			->where('invoice__provider.site_id',$this->site_id)
+			->withPivot('ref','synctoken','created_at','updated_at');
+	}
+
 	/* SCOPES */
 
 	/**