Remove test cases for redundant features

These cover handling of cases no longer returned by content_api
Remove spurious line from controller

In this instance publication can never be nil.
Remove gds-warmup-controller
Merge pull request #223 from alphagov/fix_ta_publish_rules

Fix Travel Advice publish rules
Remove old (now incorrect) comment from Gemfile.
Merge remote branch 'origin/master' into remove-rack-geo

Conflicts:
	Gemfile
	Gemfile.lock