change version number
apply_filter apply_selectors
join > joins
@join > @joins
filter > selectors
@filter > @selectors
process rules in block
refactor virtual_attributes
better spec for virtual attributes
bump version
Merge remote-tracking branch 'origin/master' into refactor-virtual-attrs

Conflicts:
	lib/lou/version.rb
Merge pull request #3 from octanner/refactor-virtual-attrs

Refactor virtual attrs