Bump to 0.2.2-SNAPSHOT
Import clj-time periodic-seq function

Following the structure and API from clj-time, import a version of it
which works on ClojureScript.

I stealled the same docs because the behavior need to be the same.
Merge pull request #13 from andrewhr/periodic-seq

Import clj-time periodic-seq function
Fix #'interval contract to match Joda Interval
Merge branch 'develop'
Release 0.2.2