class Tilt::PandocTemplate

def pandoc_options

Leave other hash keys untouched
Remove hash keys with value false
Replace hash keys with value true with symbol for key
Map tilt options to pandoc options
turn options hash into an array 
def pandoc_options
  options.reduce([]) do |sum, (k,v)|
    case v
    when true
      sum << (tilt_to_pandoc_mapping[k] || k)
    when false
      sum
    else
      sum << { k => v }
    end
  end
end