update_column and update_columns also available outside an instance

Handy and intuitives, update_column and update_columns should also be invokable from the model class.

Photo.update_column(1, :viewed_at, Time.now)
Photo.update_column([1, 2], :viewed_at, Time.now)
Photo.update_columns(1 => {:viewed_at => Time.now})
Photo.update_columns(1 => {:viewed_at => Time.now}, 2 => {:viewed_at => Date.yesterday})
Photo.update_columns([1, 2] => {:viewed_at => Time.now})

This is the fastest way to update attributes because it goes straight to the database,
but remember: __"with great power comes great responsibility"__ :+1: