Fixed deprecation version
minor #12927 Fixed deprecation version (WouterJ)

This PR was merged into the 2.7 branch.

Discussion
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Fixed deprecation version

Passing a file to `Yaml::parse()` is deprecated since 2.2 if I understand http://symfony.com/blog/security-release-symfony-2-0-22-and-2-1-7-released correctly.

| Q   | A
| --- | ---
| Fixed tickets | -
| License | MIT

Commits
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5f13343 Fixed deprecation version