ValidatorConstraintTestCase Breaks Strict Standards

## Description

`ValidatorConstraintTestCase::setUp` contains a different method signature than its parent, `PHPUnit_Framework_TestCase`. This violates PHP strict standards, causing PHPUnit to throw warnings on PHP 5.4.32.

The strict standard is reasonable in this case. Liskov Substitution Principle says all objects that are a subtype of T must be substitutable for each other. Since PHP doesn't support method overloading, variable method signatures break the LSP.

Rename the method.