Fixed the Travis build on PHP 5.3.3

Updating PHPUnit requires OpenSSL which is not available on 5.3.3 on
Travis.
minor #11107 Fixed the Travis build on PHP 5.3.3 (stof)

This PR was merged into the 2.3 branch.

Discussion
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Fixed the Travis build on PHP 5.3.3

Updating PHPUnit requires OpenSSL which is not available on 5.3.3 on Travis.

Commits
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84561d2 Fixed the Travis build on PHP 5.3.3