Move mongo adapter stuff to shared example.
Added adapter-mongo file so you do not always have to add :require op…
…tion in bundler.
Changed database test name.
Allow passing write concerns to adapter as option.
More mongo-ish storage of stuff.
* hashes get serialized in document as mongo can
* non-hashes get stored in _value key in document
* key can now be BSON::ObjectId
Initial commit. Uses hacky value key for stuff.
Going to use straight up document next.