[FrameworkBundle] Fix tests

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #10622
| License       | MIT
| Doc PR        | -

This [fixes the build](https://travis-ci.org/jakzal/symfony/builds/22199535) [![Build Status](https://travis-ci.org/jakzal/symfony.svg?branch=framework-bundle-tests-fix)](https://travis-ci.org/jakzal/symfony) by only initializing a fully configured validation service if APC is available. At the moment we only provide ApcCache for mapping' caching (out of the box). DoctrineCache is available but not configured. I also added an additional test case to verify that a validation service can be created on php >=5.5.