Added embed single unserializer test (currently failing)
Updates to tests; added explicit embedded documents.
Added more tests for unserializing embedded documents
Fixed EmbedOne with discriminator map and with target document.
Removed test that doesn't apply to this fix.
CS fixes
Merge pull request #18 from crimsonronin/Hotfix/Unserializer

Hotfix: EmbedOne Unserializer
Fixes update mode collections bug.
Various CS updates as well as some additional tests for the unserializer.
Merge pull request #20 from crimsonronin/Hotfix/UnserializerUpdate

Fixes update mode collections bug.
WIP; Fixed patch unserializing for collections.
References are failing though.
Remove bugs from reference serializers. Fix #21. Fix #22.
Merge pull request #23 from superdweebie/Hotfix/PatchUnserializer

Hotfix/patch unserializer
Extension configs were previously not merged eg. `default_db` would be omitted.
Removed test condition.
Minor tidy up. Good to go. Fixes #24
Merge pull request #25 from superdweebie/Hotfix/MergeExtensionConfig

Hotfix/merge extension config
When updating or patching a document using the unserializer, while also passing in the original document, collections would not persist correctly. They would appear in the model to be ok, but when explicitly getting them back from the DB they would be incorrect.
WIP; new unserializer test outlines errors when flushed to DB
Fixes #26