I was able to get estraverse via npm and get it work on a node app. But when when i tried to install it via bower for client side usage, the install failed saying "optionator package is not found". And when i tried to load the js file directly, it showing "Uncaught ReferenceError: exports is not defined" in the console.
Finally found the solution. Apparently the current estraverse code base is not working in a web browser but it works fine in browserify or webpack. Thus, you need to built estraverse using any of this module.
I used browserify to to built it using the code below:
browserify --standalone estraverse estraverse-master/estraverse.js > estraverse-master/build/estraverse.browser.js
Now it works fine.