Add support for bower package manager (http://bower.io/)

If you say that JDB can be used on a client side then it would be a nice idea to make it compliant with the defacto standard frontend package management system, Bower, by adding appropriate bower.json file.

Look at the repository root for existing package.json and other config files. Research bower.json format from bower.io to specify the package name, version, main files, and dependencies. The issue is about adding a bower.json file to make the library installable via Bower for client-side use.

索引モデルが issue の本文から書いたものです。