observer update and invoices creation

database/migrations/2021_01_10_164334_create_mining_tax_tables.php

@@ -41,6 +41,7 @@ class CreateMiningTaxTables extends Migration
                 $table->dateTime('last_updated');
                 $table->unsignedBigInteger('observer_id');
                 $table->string('observer_type');
+                $table->string('observer_name');
                 $table->timestamps();
             });
         }