[Feature Request] Add `feature_flags` view helper

[ybiquitous]

Hello.

I want to use the feature_flags view helper method like feature_available?.

cookie_flag/lib/cookie_flag/helper.rb

Lines 8 to 10 in a55047d

	included do
	helper_method :feature_available?
	end

While a controller provides both methods,

cookie_flag/README.md

Line 63 in a55047d

And some helper methods `feature_available?` and `feature_flags` are available.

a view provides only feature_available?.

cookie_flag/README.md

Line 77 in a55047d

`feature_available?` helper method is available.

What do you think?