Contains some configuration related constants

Constants
DATADIR = File.join( ::Gem.gempath('facets'), 'data', 'facets', 'units' )
DATADIR = File.join( ::Config::CONFIG['datadir'], 'facets', 'units' )
DATADIR = File.join( ::Config::CONFIG['datadir'], 'facets', 'units' )
DEFAULT_CURRENCY_SERVICE = Units::Converter::ExchangeRate::XMethods
  The standard service used for looking up currency exchange rates