PHPUnit configuration tweaks
Merge pull request #19 from sagikazarmark/feature/phpunit

PHPUnit configuration tweaks
Updates usage of @covers annotations in tests.

Removes the use of @coversDefaultClass in place of @covers to ensure they
are used as described by the PHPUnit documentation.

Closes #17
Merge pull request #20 from fuelphp/fix/correct_annotation_usage

Updates usage of @covers annotations in tests.