other_id can be a string

other_id can be a string (MongoId for example) and Pivotal Tracker accept this
Fix and test for error of PivotalTracker API error:

"Both the external_id and integration need to be set, but external_id is
blank"
Remove jruby environment
Merge pull request #65 from Unpakt/master

Fix for issue with marking stories as delivered using the API
Version bump to 0.5.8
Version bump to 0.5.9
Regenerate gemspec for version 0.5.9
Merge branch 'master' of github.com:jsmestad/pivotal-tracker
Removed jruby support and updated to latest gem versions
Version bump to 0.5.10
Regenerate gemspec for version 0.5.10
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/
Version bump to 0.5.11