Update dependencies

There are lots of NPM and Bower dependencies that are outdated. Most of them could be updated without any negative impact on the project.

There is already a [PR for update Angular to 1.5](https://github.com/akveo/blur-admin/pull/73)

For the other bower dependencies, I'm working with a repository where they are up to date, except for:
- **Chart.js**: latest version is 2.1.6, which is not supported by angulart-chart.js yet
- **highlight**: latest version is 9.4.0; version 9 changed how their themes are defined, and I'm not 100% sure if blur-admin uses any custom theme
- **jQuery-slimScroll**: that project appears abandoned. I believe replacing it with an alternative would be better
- **jQuery**: latest major version is 3, but it introduces many breaking changes (see the [upgrade guide](http://jquery.com/upgrade-guide/3.0/)), so I kept it on 2.2.4

Any suggestion on how we could approach this update?