Solved rollback problem in create_people_table (foreign key problem).

database/migrations/2018_09_03_090023_create_people_table.php

@@ -45,6 +45,7 @@ class CreatePeopleTable extends Migration
      */
     public function down()
     {
+        Schema::dropIfExists('person_targets');
         Schema::dropIfExists('people');
     }
 }

database/migrations/2018_09_03_091643_create_person_targets_table.php

@@ -31,9 +31,7 @@ class CreatePersonTargetsTable extends Migration
             // The type of the target. It can be either a payable or a
             // receivable. A payable is of type 'expediture' and a receivable is
             // of type 'income'.
-            $table->integer('io_type')->unsigned();
-            $table->foreign('io_type')->references('id')->on('io_types')
-                  ->onDelete('no action');
+            $table->tinyInteger('io_type');
 
             // A reference text which describes the target
             $table->string('reference');