other_id can be a string

other_id can be a string (MongoId for example) and Pivotal Tracker accept this
Update spec/pivotal-tracker/story_spec.rb
Update spec/pivotal-tracker/story_spec.rb
Added Gem version badge from http://badge.fury.io/
Merge pull request #63 from Shumkov/patch-1

other_id can be a string
Merge pull request #69 from jasonnoble/add_gem_version_badge_to_readme

Added Gem version badge from http://badge.fury.io/