use exponential backoff retry policy
Use a ceiling on ExponentialBackoffRetry

Trying to avoid pulling in a newer netflix curator

Adds lein-junit and junit dependencies with test.

Adds new configurable maximum ceiling for the retry interval, defaults
to 30s.
Change JUnit test to clojure.test test.

Pulled out the retry policy into its own class.
Revert changes for JUnit dependency
Change ceiling test to be deterministic
Rename util -> utils in new test
Remove trailing white-space
Merge remote-tracking branch 'd2r/derekd-exponential-backoff'
update intervalceiling config to explicitly say millis
update changelog