[ready for signoff] Close motions reliably. Depends on VotesController rebuild and proposal-outcome. Needs QA

**CR**: :white_check_mark:

**QA**: :white_check_mark:
> :white_check_mark: pull down locally, check app loads

> *test core functionality of feature:*
> :white_check_mark: set up cron job on clone, watched it close a motion + create event
> :ok: didn't see it create email on close (mail server not up) but this doesn't concern this feature

> *test functionality adjacent to this feature:*
> :white_check_mark: created a motion
> :white_check_mark: closing motion early not yet working 

> :ok: public/ private functionality *NA**
> :ok: logged out functionality **NA**

> :ok: test in IE 8,9 **NA**
> :white_check_mark: test in production environment

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**CO signoff**: :question:
**DO signoff**: :ok: no visual/ UI changes made 

**PO signoff**: :ok: happy for it to deploy, but slightly scared

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notes
This removes the unpredicatable "check if motion is closed when you touch a discussion" with "close all elapsed motions with an external cron job"

We need to configure our various heroku instances to call rake loomio:close_elapsed_motions (hourly would be ok) as we deploy this