build,meta: don't fail Travis for commit message

PR-URL: https://github.com/nodejs/node/pull/23739
Fixes: https://github.com/nodejs/node/issues/23737
Refs: https://github.com/nodejs/node/pull/22452


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Yuta Hiroto <hello@hiroppy.me>
Reviewed-By: Vladimir de Turckheim <vlad2t@hotmail.com>