* feat: use latest merge date/start date where available for availability text for schemes and locations
* feat: add tests for availability text
* feat: use startdate instead to track merges on schemes and locations
* feat: test startdates are set correctly on merged schemes and locations
* feat: add migration file
* feat: add scheme activating soon tests
* feat: add activating soon to scheme filtering
* feat: update scheme active_status
* feat: update tests
* refactor: lint
* feat: move merge orgs validation after orgs validation
* feat: update schema
* feat: set encoding by bom for file IO before parsing
* feat: set bom encoding for illness task as well
* feat: use StringIOs in testing and fix row count bug found
* feat: revert toheaders: false
* feat: timecop around tests
* feat: timecop around tests
* feat: fix flaky merge test
* feat: don't add old_id to new location as there is a uniqueness constraint on this attribute
* feat: don't add old_id to new scheme for consistency
* feat: update tests
* feat: don't validate on log save so they can be added to new orgs without dsas during a merge, and test
* refactor: lint
* feat: remove old_visible_id from post merge schemes/locations so they aren't searchable in bulk upload
* feat: update tests
* feat: update tests
* feat: don't add old_id to new location as there is a uniqueness constraint on this attribute
* feat: don't add old_id to new scheme for consistency
* feat: update tests
* Allow custom merge date in merge organisations service
* Allow optional merge date in merge orgs task
* Add a rake task for merging into a new organinsation