* 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
Graham Campbell
mihaileu
Jeppe Knockaert
Barry vd. Heuvel
Emir Beganović