Broken unit tests

[buskamuza]

See https://travis-ci.org/magento-engcom/php-7.2-support/jobs/342577316

See issues in the epic.

Other tests will be fixed in the scope of:

• mcrypt removed from PHP 7.2 core #10
• Warning: count(): Parameter must be an array or an object that implements Countable #7
• friendsofphp/php-cs-fixer does not support PHP 7.2 #4 (requires Symfony upgrade to a major version, which causes tests failure due to removed Symfony classes)
• Warning: get_class() expects parameter 1 to be object, null given #9

[buskamuza]

Related issues:

• Warning: count(): Parameter must be an array or an object that implements Countable #7
• Deprecated: Function create_function() is deprecated #8

[buskamuza]

Updated the description

[buskamuza]

• run unit tests locally with --ignore-platfotm-reqs for composer install
• validate on a workaround-based branch on Travis CI