:gem: bump to 2.4.0
:gem: bump to 2.4.0

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