Enable Travis and fix project setup

* Add .travis.yml
* Add vendor/ to .gitignore
* Add Gemfile.lock to the repo
* Add activerecord to the dependencies
bundle exec rake test on travis
Fixing dependency problems

* using explicit version of activerecord and nokogiri
* active_record will be loaded via vines.rb like all other dependencies
Merge pull request #6 from Zauberstuhl/fixing_dependency_problems

Fixing dependency problems