Add mongoid
Add Artefact model
Persist Artefacts to the DB
Merge branch 'master' of github.com:theodi/csvlint into feature-maintain-history

Conflicts:
	app/controllers/validation_controller.rb
	features/step_definitions/validation_steps.rb
	features/step_definitions/web_steps.rb
	features/validation.feature
Fix tests
Change upload step
Actually have a file with warnings
Test that warnings are persisted
Genericise the warning / error step
Add Mongo to Travis
Check errors are persisted
Merge branch 'master' of github.com:theodi/csvlint into feature-maintain-history

Conflicts:
	features/step_definitions/web_steps.rb
Change Artefact to Validation
Use Marshal instead of all the other cruft
Create and show validations instead of on the fly
Fix specs
Fix badge urls
Find validation by URL
Check find_by_url preserves the correct format
List validations