Changed foreign key id field name in person_targets and account_classes from

'io_type' to 'io_type_id'.

Implemented PersonTarget factory.

database/migrations/2018_09_07_090338_create_person_targets_table.php

@@ -31,8 +31,8 @@ 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('i_o_types')
+            $table->integer('io_type_id')->unsigned();
+            $table->foreign('io_type_id')->references('id')->on('i_o_types')
                   ->onDelete('no action');
 
             // A reference text which describes the target

database/migrations/2018_09_07_090452_create_account_classes_table.php

@@ -23,8 +23,8 @@ class CreateAccountClassesTable extends Migration
             $table->smallInteger('number')->unsigned()->unique();
 
             // The type of the account class.
-            $table->integer('io_type')->unsigned();
-            $table->foreign('io_type')->references('id')->on('i_o_types')
+            $table->integer('io_type_id')->unsigned();
+            $table->foreign('io_type_id')->references('id')->on('i_o_types')
                   ->onDelete('no action');
             
             // The scope of the account class.