Relax older Ruby versions
Relax older Ruby versions

gjtorikian/html-proofer,Tiger66639/html-proofer,gjtorikian/html-proofer,gjtorikian/html-proofer,gjtorikian/html-proofer,Tiger66639/html-proofer,gjtorikian/html-proofer,Tiger66639/html-proofer,Tiger66639/html-proofer,Tiger66639/html-proofer