remove the 'someday' placeholder for NULL to_be_completed_at when editing todo
redirect destroy action to previous page for TodoController
fix cannot update priority attributes via the edit page
add 'None' option for labels, add unique validation to label name, update asOptionsArray to accept a label to exclude from the option
fix: priority icon appearing more than once when there are more than labels for a todo in todo list view
refactor: remove static calls in todo controller
fix: todos are now linked to user