update migration

database/migrations/2018_07_02_104306_rename_booking_foreignkey_from_supplierbooking_table.php

@@ -17,7 +17,7 @@ class RenameBookingForeignkeyFromSupplierbookingTable extends Migration
         {
             $table->dropForeign(['book_id']);
             $table->dropColumn('book_id');
-            $table->integer('booking_id')->unsigned();
+            $table->integer('booking_id')->unsigned()->nullable;
             $table->foreign('booking_id')->references('id')->on('bookings');
         });
     }

database/migrations/2018_07_03_014020_add_billing_field_to_supplierbooking_table.php

@@ -26,6 +26,8 @@ class AddBillingFieldToSupplierbookingTable extends Migration
      */
     public function down()
     {
-        //
+        Schema::table('supplier_bookings', function (Blueprint $table) {
+            $table->dropColumn('billing_amount');
+         });
     }
 }

database/migrations/2018_07_03_014343_add_salestax_field_to_supplierbooking_table.php

@@ -26,6 +26,8 @@ class AddSalestaxFieldToSupplierbookingTable extends Migration
      */
     public function down()
     {
-        //
+        Schema::table('supplier_bookings', function (Blueprint $table) {
+            $table->dropColumn('salestax_amount');
+         });
     }
 }

database/migrations/2018_07_05_095441_add_marking_to_user_table.php

@@ -15,7 +15,7 @@ class AddMarkingToUserTable extends Migration
     {
         Schema::table('users', function($table)
         {
-            $table->string('marking');
+            $table->string('marking')->nullable();
         });
     }
 
@@ -25,7 +25,10 @@ class AddMarkingToUserTable extends Migration
      * @return void
      */
     public function down()
-    {
-        //
+    { 
+        Schema::table('users', function (Blueprint $table) {
+            $table->dropColumn('marking');
+        });
+        
     }
 }