* tests: add abstract class for all database related tests
* tests: add abstract class for all ModelsCommand related tests
* tests: add GenerateBasicPhpdoc test
* tests: add CustomDate test
* tests: remove MITM abstract TestCaseDatabase, not useful here
* tests: skip new ModelsCommand test on Laravel < 6
* tests: remove CarbonImmutable checked
Since we decided to skip for Laravel < 6.0 anyway, it's always present
* travis: use explicit test matrix and drop PHP < 7.2
* composer: use more liberal version requirements for orchestra
This is to easier satisfy when we want to use older Laravel versions on travis
* tests: add shim for assertStringContainsString for older Laravel/phpunit versions
Specifically, Laravel 5.5 works with an older phpunit version, which
does not feature assertStringContainsString
* composer: bump minimum PHP version to 7.2
* travis: explicitly install Mockery for testing older Laravel versions
* composer: make mockery a root requirement and remove the one from travis
* travis: further improve based on suggestions from https://github.com/fruitcake/laravel-cors/blob/master/.travis.yml
* tests: skip test if mixin markers are already present in model
We're also testing Laravel 5.5 which contains them (they were removed later)
* phpunit: use dedicate `Tests` namespace for tests
* tests: replace phpunit with orchestra/testbench
* phpunit: ignore result cache file
* phpunit: adapt test for newer version
* tests: add base testcase class with a helper to run/assert commands
* tests: add test for ide-helper:eloquent
* travis: add global default variables
* travis: disable xdebug, speeds up running tests
* travis: convert php versions to build matrix for environment vars
* travis: only run phpcs/phpunit when the env vars signal it
However phpcs only runs with one test combination from the matrix,
not necessary to execute it every time.
Markus Podar
Yuta Nagamiya
Barry vd. Heuvel