chore(build): eslint all js files, and use js for all generated files (#331)

Author: yoshi-automation

handwritten/pubsub/samples/.eslintrc.yml

@@ -3,4 +3,4 @@ env:
   mocha: true
 rules:
   no-console: off
-  no-unused-vars: off
+  node/no-missing-require: off