Fix version constraints failures.

[Maikuolan]

324 and #325 currently suffer from tests failures, which seem to originate due to the PHP version constraints specified by composer.json. This PR should, hopefully, fix those failures (when, of course, they're eventually ready to be merged later).

(Changes to composer.lock are a result of php composer.phar update performed after updating composer.json).

[Maikuolan]

The only failure remaining here now, seems to be because of Scrutinizer. But, I don't think that's our fault, because Zest isn't even mentioned anywhere at all in the stack trace:

PHP Fatal error:  Array and string offset access syntax with curly braces is no longer supported in /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/src/Config.php on line 399
PHP Stack trace:
PHP   1. {main}() /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/bin/phpcs:0
PHP   2. PHP_CodeSniffer\Runner->runPHPCS() /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/bin/phpcs:18
PHP   3. PHP_CodeSniffer\Autoload::load($class = 'PHP_CodeSniffer\\Config') /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/src/Runner.php:67
PHP   4. PHP_CodeSniffer\Autoload::loadFile($path = '/home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/src/Config.php') /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/autoload.php:134
PHP Fatal error:  Array and string offset access syntax with curly braces is no longer supported in /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/src/Config.php on line 399
PHP Stack trace:
PHP   1. {main}() /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/bin/phpcs:0
PHP   2. PHP_CodeSniffer\Runner->runPHPCS() /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/bin/phpcs:18
PHP   3. PHP_CodeSniffer\Autoload::load($class = 'PHP_CodeSniffer\\Config') /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/src/Runner.php:67
PHP   4. PHP_CodeSniffer\Autoload::loadFile($path = '/home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/src/Config.php') /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/autoload.php:134
Setting configuration file : /home/scrutinizer/tmp/scrutinizer_toolconfigs/phpcs.xml
PHP Fatal error:  Array and string offset access syntax with curly braces is no longer supported in /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/src/Config.php on line 399
PHP Stack trace:
PHP   1. {main}() /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/bin/phpcs:0
PHP   2. PHP_CodeSniffer\Runner->runPHPCS() /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/bin/phpcs:18
PHP   3. PHP_CodeSniffer\Autoload::load($class = 'PHP_CodeSniffer\\Config') /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/src/Runner.php:67
PHP   4. PHP_CodeSniffer\Autoload::loadFile($path = '/home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/src/Config.php') /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/autoload.php:134

I guess, somebody made a typo somewhere in PHP_CodeSniffer, maybe..? "ಠ_ಠ

(Eh.. Oh well.. At least, we've done everything that we can, I think).

[lablnet]

The only failure remaining here now, seems to be because of Scrutinizer. But, I don't think that's our fault, because Zest isn't even mentioned anywhere at all in the stack trace:

PHP Fatal error:  Array and string offset access syntax with curly braces is no longer supported in /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/src/Config.php on line 399
PHP Stack trace:
PHP   1. {main}() /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/bin/phpcs:0
PHP   2. PHP_CodeSniffer\Runner->runPHPCS() /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/bin/phpcs:18
PHP   3. PHP_CodeSniffer\Autoload::load($class = 'PHP_CodeSniffer\\Config') /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/src/Runner.php:67
PHP   4. PHP_CodeSniffer\Autoload::loadFile($path = '/home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/src/Config.php') /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/autoload.php:134
PHP Fatal error:  Array and string offset access syntax with curly braces is no longer supported in /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/src/Config.php on line 399
PHP Stack trace:
PHP   1. {main}() /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/bin/phpcs:0
PHP   2. PHP_CodeSniffer\Runner->runPHPCS() /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/bin/phpcs:18
PHP   3. PHP_CodeSniffer\Autoload::load($class = 'PHP_CodeSniffer\\Config') /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/src/Runner.php:67
PHP   4. PHP_CodeSniffer\Autoload::loadFile($path = '/home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/src/Config.php') /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/autoload.php:134
Setting configuration file : /home/scrutinizer/tmp/scrutinizer_toolconfigs/phpcs.xml
PHP Fatal error:  Array and string offset access syntax with curly braces is no longer supported in /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/src/Config.php on line 399
PHP Stack trace:
PHP   1. {main}() /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/bin/phpcs:0
PHP   2. PHP_CodeSniffer\Runner->runPHPCS() /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/bin/phpcs:18
PHP   3. PHP_CodeSniffer\Autoload::load($class = 'PHP_CodeSniffer\\Config') /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/src/Runner.php:67
PHP   4. PHP_CodeSniffer\Autoload::loadFile($path = '/home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/src/Config.php') /home/scrutinizer/.analysis/phpcs/vendor/squizlabs/php_codesniffer/autoload.php:134

I guess, somebody made a typo somewhere in PHP_CodeSniffer, maybe..? "ಠ_ಠ

(Eh.. Oh well.. At least, we've done everything that we can, I think).

yeah agreed