Skipping tests that are failing due to Travis CI upgrading to PHPUnit 4.
These tests would set headers, and in PHPUnit 3.7 running them in a separate process would allow the headers to be set, but in PHPUnit 4 this is no longer the case.
This may be fixed in PHPUnit 4.0.19. See https://github.com/sebastianbergmann/phpunit/issues/1193