Upgrade datomic
Remove old vendor files
Update datomic in cloud formation template
Upgrade core.async. Kioo is currently preventing
updating om and clojurescript
Update dependencies

- clojure
- clojurescript
- core.async
- kioo
Test end-to-end transit
Convert json requests to use transit
Upgrade OM. Remove kioo.

Kioo was broken in latest om. I like what they're doing but this is the
2nd or 3rd time broken kioo has prevented upgrading something. Pulling
it, for now.
Merge pull request #24 from neo/transit

Use Transit for data interchange format