update all models with validations, idexes and required fields. Add support to generate slug when name is set.
update rails version and add rspec and factory girl
add rspec, factory girl, shoulda_matcher. Insert tests for Step, Project, User
change id with slug in finders
Merge branch 'master' of github.com:RACPractice/kanban

Conflicts:
	app/models/task.rb
	app/models/work_item.rb
	db/schema.rb