-add: printing lines from file in DropJob
bump version number
-add: more error handling
-add: activesupport dependency
-add: storage engine
-add: URL and Drop data classes
-add: new files to crawly-core.rb
-change: using URL class instead of hashes
-rename: jobs/drop.rb to jobs/drop_job.rb
-remove: data/drop.rb (because qless does not accept custom classes)
bump version