Initial commit

It's now a standalone app to keep the environmental impact of one
separate from the other, as suggestes by @huntc
Update README.md
Let mongo filter the mongo-id

As suggested by @sgodbillon

https://github.com/TechEmpower/FrameworkBenchmarks/pull/166#discussion_r3869739
Merge branch 'play-reactivemongo' of https://github.com/Skamander/FrameworkBenchmarks into Skamander-play-reactivemongo
update setup file to point to play-scala-mongodb