Use PSR-1 for PHPUnit TestCase

[carusogabriel]

Use PSR-1 while extending PHPUnit TestCase class. This will help us when to migrate to PHPUnit 6, that no longer support snake case namespaces.

[alcaeus]

This needs an update of the phpunit requirement in composer.json. Not all versions that satisfy ^4.8 include the forward compatibility layer. I suggest using ^4.8.36|^5.7|^6.4 instead of ^4.8.

[carusogabriel]

@alcaeus I'll update to ^4.8.36 only. PHPUnit 5 has some deprecated methods, and 6 uses PHP 7, and we will need to work on that later.

[jmikola]

Manually merged in d4583a9. Thanks!

@alcaeus: I noticed that there were two outstanding issues with allowing ^5.7|^6.4 in composer.json:

• We currently have a number of tests that perform no assertions (e.g. they construct an object to ensure that no exceptions are thrown for invalid arguments). PHPUnit now warns against such risky tests unless we disable the warning in our configuration.
• We have several tests that expect a PHPUnit_Framework_Error_Warning exception (as part of their assertion for an internal PHP warning). The PHPUnit 6 compatibility layer added in 4.8.36 and 5.7.21 did not include namespaced aliases for the exception classes, so we can't generalize those tests for all three PHPUnit verisons.

For the time being, we'll need to remain on 4.8.36.

[alcaeus]

PHPUnit now warns against such risky tests unless we disable the warning in our configuration.

For individual tests, there is a doesNotPerformAssertions annotation you can add to the tests in question. As for the warnings, that's indeed an issue that can't be fixed - only thing you could do is adding your own compatibility layer using class_alias.

[jmikola]

Sounds good. I've opened PHPLIB-294 to track that.