Update composer.json

Laravel 5.7

Apply fixes from StyleCI (laravel-doctrine#334)

[ci skip] [skip ci]

Accepting symfony/serializer#~4.0 (laravel-doctrine#319)

Since Laravel 5.6 works with symfony/serializer#~4.0 its time to upgrade?

[FEATURE]Update doctrine/orm to 2.6 (laravel-doctrine#311)

* Update doctrine/orm to 2.6

* Fix failing test

Add return statement to Illuminate::resetManager() (laravel-doctrine#250

)

Update related tests to check that behavior

Laravel 5.6

Merge branch '1.3' into 1.4

Laravel 5.5 update

Update README.md