Add memento to chef
Updates after review
Correct names
Add clearwater-infrastructure box type
Merge branch 'add-clearwater-infrastructure-box'
Enable gemini
Merge pull request #134 from Metaswitch/add_memento

[No reviewer] Add memento
Update 12.04 EC2 base images
Also update the default image
Merge pull request #135 from Metaswitch/latest12.04

Reviewer Matt - Update 12.04 EC2 base images