Remove old locations config from number10 site and fixture

I think this used to be used by Redirector, but it isn't imported into
Transition so has no effect now from here. There's already a rule in Bouncer
to do this for number10:

https://github.com/alphagov/bouncer/blob/1fb429e083ed989a5b5164e976a65f364afc157e/lib/bouncer/fallback_rules.rb#L28-L30

data/transition-sites/number10.yml

@@ -6,8 +6,3 @@ tna_timestamp: 20130109092234
 homepage_furl: www.gov.uk/number10
 homepage: https://www.gov.uk/government/organisations/prime-ministers-office-10-downing-street
 css: number10
-locations:
-- path: ^/news/?([_0-9a-zA-Z-]+)?/([0-9]+)/([0-9]+)/(.*)-([0-9]+)$
-  operation: ~*
-  status: 301
-  new_url: http://www.number10.gov.uk/news/$4

tests/fixtures/sites/paths.yml

@@ -3,7 +3,3 @@ site: paths
 host: paths.local
 aliases:
     - alias1.paths.local
-locations:
-    - path: /
-      new: http://www.example.com/foo/bar
-      status: 301