chore: run node@12 in travis

sorrycc · sorrycc · commit 60c2a7af70fb · 2019-09-05T15:38:03.000+08:00
diff --git a/.travis.yml b/.travis.yml
@@ -3,6 +3,7 @@ language: node_js
 node_js:
   - "8"
   - "10"
+  - "12"
 
 before_script:
   - npm run build
