Forward compatibility with PHPUnit 6

[carusogabriel]

As did in others Reactphp repos, I use the PHPUnit\Framework\TestCase notation instead of PHPUnit_Framework_TestCase while extending our TestCases. This helped us migrate to PHPUnit 6, that no longer support snake case class names.

I just need to bump PHPUnit version to ^4.8.35 and ^5.7, that support this namespace.

[carusogabriel]

Ok, we are facing some issues with this update. I have some solutions, and I want your opinion:

• Just update to PHPUnit 5, because PHPUnit has big breaking changes;
• Drop PHPUnit 4 support, but require minimum PHP 5.6;

[clue]

@Gabriel-Caruso Thanks for keeping up with this! I've updated reactphp/socket#133 to add a very simple BC layer to support all PHPUnit versions, perhaps you can look into implementing a similar logic here? 👍

[carusogabriel]

@clue Actually, no, because there's no setExpectedMessage method for PHPUnit 4. What should we do?

[clue]

@Gabriel-Caruso Not sure I follow, have you seen the setExpectedException() BC layer from the above PR (https://github.com/reactphp/socket/pull/133/files#diff-d4c8c6dc8769324fc27cfdac19f05cafR85)? This works out of the box on PHPUnit 4 and will redirect to new method calls on newer versions of PHPUnit.

[carusogabriel]

@clue Done, everything is working now 🎉

[clue]

Thanks for keeping up with this, changes LGTM! 👍

[carusogabriel]

Anything else that should be done here?

[WyriHaximus]

Nope LGTM 👍