ci(travis): update TravisCI to Node 10

Author: arthurdenner

.travis.yml

@@ -4,7 +4,7 @@ cache:
     - ~/.npm
 notifications:
   email: false
-node_js: '8'
+node_js: '10'
 install: npm install
 script: npm run validate
 after_success: test $TRAVIS_BRANCH = "master" && test $TRAVIS_PULL_REQUEST = "false" && npx semantic-release