Update Travis config (#196)
Update Travis config (#196)

* Remove matrix exclusions since they're useless

* Add PHP 7.3 to the Matrix

* Include PHP 7.4 and introduce stages

* Exclude Laravel 5.3 for PHP 7.3 + 7.4snapshot

* Fix dependencies for code style job

* Disable progress download output for composer

getsentry/sentry-laravel,getsentry/sentry-laravel