* Update bundler-audit to version 0.5.0
* Update oj to version 3.0.6
* Update http-form_data to version 1.0.2
* Update parallel to version 1.11.2
* Update rails-i18n to version 5.0.4
* Update rack-protection to version 2.0.0
* Update haml to version 5.0.1
* Update scss_lint to version 0.53.0
* Relax requirement on i18n-tasks
* Remove haml and haml_lint gem requirement