build: do not lint on non-PR Travis builds
Do not run any linting at all when TRAVIS_PULL_REQUEST
is false
.
This would otherwise break Travis CI for master
and release branches.
Refs: https://github.com/nodejs/node/pull/24030
Checklist
-
make -j4 test
(UNIX), orvcbuild test
(Windows) passes -
commit message follows commit guidelines