Fix name in bower.json

From the [bower.json spec on the `name` attribute](https://github.com/bower/bower.json-spec#name):

> * Should be slug style for simplicity, consistency and compatibility. Example: `unicorn-cake`
> * Lowercase, a-z, can contain digits, 0-9, can contain dash or dot but not start/end with them.

Currently, `bower install scroll-depth` installs older version 0.4.1. This change should fix that issue.