[Video Setting] Integrating volume slider

- bower updated add dependency on `angular-bootstrap-slider`
- video setting HTML template updated to include `<slider>`
- translations updated with more labels
- e2e test HTML updated to include ui.bootstrap-slider dependencies and added to the `testapp`
- demo updated to include dependencies on angular-bootstrap-slider
Merge pull request #178 from stulees/chore/video-setting-volume

[Video Setting] Integrating volume slider