Show summary of copyrights for a scan in html-app

[jdaguil]

Narrative: I want to quickly see the number and proportion of copyrights detected from a scan. This will help me estimate the primary owner for a package.
Context: A Treemap from D3.js has been visited in the past. We may want to offer several different graphic/chart views from D3.js.
Acceptance Criteria:
- Scenario 1: When a user runs a scan on a codebase, a visual summary of the high level copyright stats would be displayed in the HTML app.

[pombredanne]

As a first step we need to collect copyright holders in the scan

[nspsjsu]

Issue resolved