This reverts commit 3e862b1aa1.
Valgrind reports memory leaks with all test on PHP with ZTS,
which it doesn't do locally. More investigation needed ...
Test against php 5.3, 5.4, and 5.5 -- which incidentally works around
the 'make test always succeeds' bug in php 5.3 and 5.4
(https://bugs.php.net/bug.php?id=60285).
('make test' may always succeed, but we still test against 5.3 and 5.4 to
ensure that we build correctly w/o errors on these php versions.)