Data migration to correct slugs

Redirections required in puppet:

'/government/people/michael-spur' =>'/government/people/michael-spurr'
'/government/people/rita-kabaria-french' => '/government/people/rita-french'
Merge pull request #380 from alphagov/correct-some-slugs

Data migration to correct a couple of slugs for people

https://www.pivotaltracker.com/story/show/46616541