close #46 Enhancement: Bill and Invoice improve total status and system

app/Models/Income/InvoiceTotal.php

@@ -0,0 +1,25 @@
+<?php
+
+namespace App\Models\Income;
+
+use App\Models\Model;
+use App\Traits\DateTime;
+
+class InvoiceTotal extends Model
+{
+    use DateTime;
+
+    protected $table = 'invoice_totals';
+
+    /**
+     * Attributes that should be mass-assignable.
+     *
+     * @var array
+     */
+    protected $fillable = ['company_id', 'invoice_id', 'code', 'name', 'amount', 'sort_order'];
+
+    public function invoice()
+    {
+        return $this->belongsTo('App\Models\Income\Invoice');
+    }
+}