Remove the services dropdown from the header

* Be friendlier with our signed in as message
* Make greeting match Maslow
* Make the sign out link clearer
* Remove the unnecessary drop down
Merge pull request #68 from alphagov/no-service

Remove the services dropdown from the header
Fix organisations feature

* Signed in text has changed
Merge pull request #70 from alphagov/fix-signed-in-tests

Fix organisations feature