Article migration

```
Schema::create('articles', function (Blueprint $table) {
            $table->increments('id');
            $table->integer('people_id');
            $table->string('title');
            $table->timestamps();
            $table->foreign('author_id')->references('id')->on('people');
        });

```

People Migration

```
Schema::create('people', function (Blueprint $table) {
            $table->increments('id');
            $table->string('first_name');
            $table->string('last_name');
            $table->string('twitter');
            $table->timestamps();
        });

```

Error

```
 SQLSTATE[HY000]: General error: 1005 Can't create table `article`.`#sql-1204_c` (errno: 150 "Foreign key constraint is incorrectly formed") (SQL: alter tab
  le `articles` add constraint `articles_author_id_foreign` foreign key (`author_id`) references `people` (`id`))

```

i dont know what im doing wrong, both entity is consistent for me, i do not know why im receiving error 150