Add PostgreSQL replication script

Dumps stagecraft and imports it into dev vm. This requires that no users
are connected to the dev vm PostgreSQL, if there are then it will blow
up.
Stop collectd while restoring

We need to remove collectd's connection to the stagecraft db so the
restore can happen.
squash-me reset password
fixup: drop db before restoring
Add basic admin classes for transforms

As a developer, this will make testing things easier.
Merge pull request #279 from alphagov/transforms-admin

Add basic admin classes for transforms
Tidy up replicate script

Replaced a reference to mongo and backdrop, which is where this script
is copied from.

Enabled removal of the dump as it won't be needed after completion.
Merge pull request #280 from alphagov/feature/db-replication

Feature/db replication
Add rate transforms
WIP - Add user satisfaction
Only work on Prison Visits dashboard for now
Create dataset for data group and data type
Exclude duration query parameter
Convert migration script to use Dashboard model
wip update modules
Force transform to run when migration has started