This should fix the problems that parameters in tests like these, do not end up in the controller:
```php
$this->json('GET', '/something', ['var' => 'x']);
```

With this change you can again just do this in your Controller, and it will work:
```php
$input = $this->validate($request, [
  'var' => 'required',
]);
```

With the default AlbertCht\lumen-testing the above would fail with `var.required`, even though you set it.

Upgrade distro to bionic (Ubuntu 18.04 LTS) so we have PHP 7.1-7.4 available:

https://docs.travis-ci.com/user/languages/php/#choosing-php-versions-to-test-against

I notice that Travis CI doesn't quite seem to know that tests have ended. Not sure if this fixes anything.

Fix for Issue 13, could not send parameters to json endpoints

Add testing for Lumen 5.7, 5.8 and 6.x, plus PHP 7.1-7.4

support lumen 7.0