Removed exception if publishable column does not exist.  I've found this causes pain during migrations for models that are defined as publishable but for which the publishable column itself is created in a subsequent migration.
added travis config
Merge pull request #2 from tinynumbers/allow-missing-publishable-column

Don't throw exception if publishable column does not (yet) exist.
added travis build status icon to readme
Regenerate gemspec for version 1.0.2