Unable to register user - photo_id does not have a default value (Version 5.6) - laravel-5.6

Question

I have my users and photos tables create. Now that I added the photo_id into my users table, I am unable to register a user and it gives me an error saying that photo_id does not have a default value.
Here my User Model:
<?php
namespace App;
use Illuminate\Notifications\Notifiable;
use Illuminate\Foundation\Auth\User as Authenticatable;
class User extends Authenticatable
{
use Notifiable;
/**
* The attributes that are mass assignable.
*
* #var array
*/
protected $fillable = [
'name', 'email', 'password','photo_id'
];
public function photo(){
return $this->belongsTo('App\Photo');
}
/**
* The attributes that should be hidden for arrays.
*
* #var array
*/
protected $hidden = [
'password', 'remember_token',
];
}
Photo Model:
<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class Photo extends Model
{
//
protected $fillable = ['path'];
}
Users Migration table
class CreateUsersTable extends Migration
{
/**
* Run the migrations.
*
* #return void
*/
public function up()
{
Schema::create('users', function (Blueprint $table) {
$table->increments('id');
$table->integer('photo_id');
$table->string('name');
$table->string('email')->unique();
$table->string('password');
$table->rememberToken();
$table->timestamps();
});
}
/**
* Reverse the migrations.
*
* #return void
*/
public function down()
{
Schema::dropIfExists('users');
}
}
And here My photo migration
<?php
use Illuminate\Support\Facades\Schema;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;
class CreatePhotosTable extends Migration
{
/**
* Run the migrations.
*
* #return void
*/
public function up()
{
Schema::create('photos', function (Blueprint $table) {
$table->increments('id');
$table->string('path');
$table->timestamps();
});
}
/**
* Reverse the migrations.
*
* #return void
*/
public function down()
{
Schema::dropIfExists('photos');
}
}
This is what I see when I try to register a user: