Merge pull request webpack#8747 from webpack/deps/node-12

update node 12 nightly version

Author: sokra

.travis.yml

@@ -38,7 +38,7 @@ matrix:
     - os: linux
       node_js: "10"
       env:
-        - NODEJS_VERSION=v12.0.0-nightly20181024bb79e768e5
+        - NODEJS_VERSION=v12.0.0-nightly20190206686043e76e
         - YARN_EXTRA_ARGS="--ignore-engines"
         - NO_WATCH_TESTS=1
         - JEST="--maxWorkers=2 --cacheDirectory .jest-cache"