[CI] use NodeJS 10 instead 8 for travis CI (DefinitelyTyped#38946)

Author: Flarna

.travis.yml

@@ -1,10 +1,10 @@
 language: node_js
 node_js:
-  - 8
+  - 10
 
 notifications:
   email: false
 
 script:
  - npm run test
- - if [[ $TRAVIS_EVENT_TYPE == "cron" ]]; then npm run update-codeowners || travis_terminate 1; fi
+ - if [[ $TRAVIS_EVENT_TYPE == "cron" ]]; then npm run update-codeowners || travis_terminate 1; fi