Move discount columns migration to a separate file

database/migrations/2020_01_08_000000_core_v200.php

@@ -240,11 +240,6 @@ class CoreV200 extends Migration
         Schema::table('users', function (Blueprint $table) {
             $table->string('landing_page', 70)->nullable()->default('dashboard');
         });
-
-        Schema::table('invoice_items', function (Blueprint $table) {
-            $table->double('discount_rate', 15, 4)->default('0.0000');
-            $table->string('discount_type')->default('normal');
-        });
     }
 
     /**

database/migrations/2020_03_20_183732_add_discount_columns_invoice_items_table.php

@@ -0,0 +1,40 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+class AddDiscountColumnsInvoiceItemsTable extends Migration
+{
+    /**
+     * Run the migrations.
+     *
+     * @return void
+     */
+    public function up()
+    {
+        Schema::table(
+            'invoice_items',
+            function (Blueprint $table) {
+                $table->double('discount_rate', 15, 4)->default('0.0000')->after('tax');
+                $table->string('discount_type')->default('normal')->after('discount_rate');
+            }
+        );
+    }
+
+    /**
+     * Reverse the migrations.
+     *
+     * @return void
+     */
+    public function down()
+    {
+        Schema::table(
+            'invoice_items',
+            function (Blueprint $table) {
+                $table->dropColumn('discount_rate');
+                $table->dropColumn('discount_type');
+            }
+        );
+    }
+}