Update sami/sami to 2.*
Update phpunit/phpunit to 4.3.*
Update squizlabs/php_codesniffer from 1.5.2 to 1.5.5
Merge pull request #516 from bantu/dev-deps-update

Update development dependencies

* bantu/dev-deps-update:
  Update squizlabs/php_codesniffer from 1.5.2 to 1.5.5
  Update phpunit/phpunit to 4.3.*
  Update sami/sami to 2.*