Revert "Merge branch 'add/lint' into 'master'"

.gitlab-ci.yml

README.md

camo-image-proxy.php

inc/class-options-page.php

inc/class-options.php

inc/class-rewrite-content.php

inc/class-rewrite-urls.php

inc/class-url.php

inc/functions.php

inc/trait-singleton.php

languages/camo-image-proxy.pot

readme.txt