Enforced compression on compiled css file
Add an unwired switch for optimizely.
Merge pull request #578 from guardian/sass

Enforced compression on compiled css file
Merge pull request #579 from guardian/optimizely-switch

Add switch for optimizely.
Merge branch 'master' of github.com:guardian/frontend into picture-desk
Made "blocks" more specific so it does not have unintended consequences