Fix checklist_add_item call
Fix checklist_add_item call

Added `!!` idiom to ensure values generated by new
`list_for_completed_work?` and `list_for_in_progress_work?` methods is
`true|false`, since the `Trello::Checklist#add_item` method requires
an actual boolean for `checked` state.

dobbymoodge/sprint_tools,openshift/sprint_tools,openshift/sprint_tools,dobbymoodge/sprint_tools