Fix package namespace and update deps

• myclabs/deep-copy updated from 1.4.0 to 1.5.0
  See changes: myclabs/[email protected]
  Release notes: https://github.com/myclabs/DeepCopy/releases/tag/1.5.0
• symfony/yaml updated from v2.7.5 to v2.7.6
  See changes: symfony/[email protected]
  Release notes: https://github.com/symfony/yaml/releases/tag/v2.7.6
• phpunit/phpunit updated from 5.0.6 to 5.0.9
  See changes: sebastianbergmann/[email protected]
  Release notes: https://github.com/sebastianbergmann/phpunit/releases/tag/5.0.9