Upgrade haml-coffee.
Upgrade haml-coffee.

This fixes #5 where boolean attribute logic is also performed on String literals.
With this upgrade only code attributes with true/false triggers the boolean
attribute logic.

nfm/haml_coffee_assets,ipmobiletech/haml_coffee_assets,spodlecki/haml_coffee_assets,emilioforrer/haml_coffee_assets,nekath/haml_coffee_assets,wantedly/haml_coffee_assets,jcouyang/haml_coffee_assets,Verba/haml_coffee_assets,nfm/haml_coffee_assets,wantedly/haml_coffee_assets,ipmobiletech/haml_coffee_assets,RatioClothing/haml_coffee_assets,emilioforrer/haml_coffee_assets,dlandau/haml_coffee_assets,xronos-i-am/haml_coffee_assets,Verba/haml_coffee_assets,Sija/haml_coffee_assets,RatioClothing/haml_coffee_assets,jcouyang/haml_coffee_assets,netzpirat/haml_coffee_assets,dlandau/haml_coffee_assets,Sija/haml_coffee_assets,xronos-i-am/haml_coffee_assets,spodlecki/haml_coffee_assets,nekath/haml_coffee_assets,netzpirat/haml_coffee_assets,omadahealth/haml_coffee_assets,omadahealth/haml_coffee_assets