Updated dependencies versions and library version

Changed friend version from 0.2.2-SNAPSHOT to 0.2.3-SNAPSHOT

Updated versions of third-party libraries:
- ring-core 1.2.0 -> 1.3.1
- slingshot 0.10.2 -> 0.12.1
- commons-codec 1.6 -> 1.9
- core.cache 0.6.2 -> 0.6.4
- ring-mock 0.1.1 -> 0.1.5
- compojure 1.1.5 -> 1.2.1
- ring 1.2.0 -> 1.3.1
- clj-http 0.3.6 1.0.1