Add rake task for updating the organisation slug

This rake task allows for slugs to be changed for an organisation. This task will only make changes however to signon-o-tron and is expected to be run from a higher level fabric task.
Merge pull request #287 from Themitchell/feature/rake-task-for-changing-organisation-slugs

Add rake task for updating the organisation slug
Update user json to reflect user suspension

www.agileplannerapp.com/boards/173808/cards/5886

Add a disabled flag to the user json that gets
synced with the user's apps, so that they can
treat suspended users differently.

Exclude permission information to be sent for a
suspended user, because the suspended user should
not be able to perform any operation. Whenever the
user's account gets un-suspended we can send the
correct permissions back to the user's apps.
Sync permissions with user's apps on suspension

www.agileplannerapp.com/boards/173808/cards/5886

Updated the inactive user suspender to log-out
the user from all apps when they're suspended.
Rake to push permissions information to apps

www.agileplannerapp.com/boards/173808/cards/5886

Will be used during deploy to sync user permission
to apps that they have permissions to use.
Merge pull request #288 from alphagov/propogate-suspension-status-of-users

Propogate suspension status of users
Fix update_organisation_slug rake task.

It was referencing non-existent variables.
Merge pull request #289 from alphagov/fix_org_update_task

Fix update_organisation_slug rake task.