Add LICENSE, AUTHORS, CONTRIBUTORS files

[davelab6]

Filing an issue for me to add these via PR :)

• [ ] OFL.txt in master #4
• [ ] LICENSE.txt with Apache in gh-pages
• [ ] AUTHORS in master
• [ ] CONTRIBUTORS in gh-pages
• [ ] AUTHORS in master
• [ ] CONTRIBUTORS in gh-pages
• [ ] master README updated with licensing note
• [ ] gh-pages README created