Simplify PHPUnit config

[javiereguiluz]

A continuation of #627 ... if I remove this setting, I see this error in every test:

20) App\Tests\Controller\DefaultControllerTest::testSecureUrls with data set #3 ('/en/admin/post/1/edit')
Symfony\Component\DependencyInjection\Exception\EnvNotFoundException:
Environment variable not found: "APP_SECRET".

symfony-demo/vendor/symfony/dependency-injection/Container.php:451
symfony-demo/var/cache/test/srcTestDebugProjectContainer.php:3081
symfony-demo/vendor/symfony/dependency-injection/Container.php:335
symfony-demo/var/cache/test/srcTestDebugProjectContainer.php:1670
symfony-demo/vendor/symfony/dependency-injection/Container.php:335
symfony-demo/var/cache/test/srcTestDebugProjectContainer.php:809
symfony-demo/vendor/symfony/event-dispatcher/EventDispatcher.php:145
symfony-demo/vendor/symfony/event-dispatcher/ContainerAwareEventDispatcher.php:110
symfony-demo/vendor/symfony/event-dispatcher/Debug/TraceableEventDispatcher.php:256
symfony-demo/vendor/symfony/event-dispatcher/Debug/TraceableEventDispatcher.php:141
symfony-demo/vendor/symfony/http-kernel/HttpKernel.php:129
symfony-demo/vendor/symfony/http-kernel/HttpKernel.php:68
symfony-demo/vendor/symfony/http-kernel/EventListener/ExceptionListener.php:50
symfony-demo/vendor/symfony/event-dispatcher/Debug/WrappedListener.php:104
symfony-demo/vendor/symfony/event-dispatcher/EventDispatcher.php:212
symfony-demo/vendor/symfony/event-dispatcher/EventDispatcher.php:44
symfony-demo/vendor/symfony/event-dispatcher/Debug/TraceableEventDispatcher.php:146
symfony-demo/vendor/symfony/http-kernel/HttpKernel.php:230
symfony-demo/vendor/symfony/http-kernel/HttpKernel.php:79
symfony-demo/vendor/symfony/http-kernel/Kernel.php:171
symfony-demo/vendor/symfony/http-kernel/Client.php:61
symfony-demo/vendor/symfony/framework-bundle/Client.php:131
symfony-demo/vendor/symfony/browser-kit/Client.php:315
symfony-demo/tests/App/Controller/DefaultControllerTest.php:76
symfony-demo/vendor/symfony/phpunit-bridge/bin/.phpunit/phpunit-5.7/phpunit:5

Caused by
Symfony\Component\DependencyInjection\Exception\EnvNotFoundException:
Environment variable not found: "APP_SECRET".

Has anyone a solution for this problem? Thanks!

[yceruto]

Sorry I didn't see this PR before submit #630.

Likely I expressed myself wrong here https://github.com/symfony/symfony-demo/pull/627/files#r136131993 I meant just the comment part, the env variable should be there to make tests work.

Other workaround could be create a tests/bootstrap.php file to load the .env file with the advantage of override only the necessary vars like DATABASE_URL (useful for big project with a lot env vars) but still setting it in phpunit.xml.dist is simpler by now. I means, they are two required environment variables ATM.

Also, we don't need either APP_ENV or APP_DEBUG as they have defaults test and true respectively:

https://github.com/symfony/symfony/blob/ec7a2b14ca5f8ff112bb16b96974596c31e689c3/src/Symfony/Bundle/FrameworkBundle/Test/KernelTestCase.php#L180-L183

[javiereguiluz]

Closing in favor of #630.