Add initial Data migration implementation
Add data migration files
Deduplicate reporter setting
Run data migrations inside transactions
Add missing data migration
Add Footnote 05976 data migration
Reverse database.yml changes
Add migration redo support
Fix case related typo
Refactor TaricImporter

Split it out into smaller components and make more object oriented -
testable.

Also ensures that conformance validations happen in reverse (to
transaction) sequence to avoid false positive conformance errors. E.g.:
footnote gets inserted before footnote description period and we get an
error about footnote missing at least one description period. This
changes the sequence so that description period gets inserted (and
validated) first.
Adjust namespace for attribute mutators

Also add integration spec for TaricImporter to make sure we import
complex entities like Measure
Remove schema migrations that duplicate data migrations

Will be doing a schema reload so this change is ok on that basis
Remove other unnecessary migrations
Add one missing data migration
Remove abbreviation column removing migration

This should not be here as no abbreviation columns are now being created
Merge pull request #91 from alphagov/data_migrations

Data migrations
Merge pull request #94 from alphagov/taric-validator-fix

Taric importer refactoring and validation fix