Development versions should be snapshots
Upgrade to Metrics 2.2
Development versions should be snapshots, take 2
Development versions should be snapshots, take 3
Ignore Leiningen checkouts
Test against Clojure 1.3-1.6

1.2.1 can be added the same way as needed, but it hardly matters
much these days.
Depend on Cheshire 5.0.2
Don't use version ranges, depend on Clojure 1.5.1