project-wide change of copyright, package names, and maven groupIds

copyright: Andy Dennie -> Fizz Buzz LLC
java package names: com.andydennie.* -> com.fizzbuzz.*
maven groupId: com.andydennie.vroom -> com.fizz-buzz.vroom
copyright changes
added Contributing.md file
Update CONTRIBUTING.md
Rewrite function to fully migrate data
Merge branch 'all-entity-migration' of https://github.com/mogupta/vroom into mogupta-all-entity-migration