Replace bower by NPM

Here is what I did when I tried to replace Bower by NPM for
MEANJS-0.5.0

bower configuration:
[gist https://gist.github.com/vanduc1102/dd97c58d5900655acb98d45b1505fa12]

That mean all the frondend libs will store in public/lib folder.

Now after I moved all the libs to package.json,
Oops, there is a small change, angular-bootstrap in will change to
angular-ui-bootstrap with NPM

[gist https://gist.github.com/vanduc1102/fb18241724ed4aacb6b8afb7b3ba2e62]

And a new gulp task:
[gist https://gist.github.com/vanduc1102/a70ed41f476dd4b5c6465747b18f88ea]

Update package.json
[gist https://gist.github.com/vanduc1102/d10d0c99ec1b4281c6a321e2ff213c67]