RP SVG - ironing out SVG module, and making SVG-refactor-2.rb working
RP SVG - removing NUMBER_OF_TOSSES, no reason for this constant to exist
RP SVG - decreasing parameters for spark by pushing calculations logic
into the 'spark' method
RP SVG - moving points into 'sparkline' since it's the only method cares
about points. Updating x_axis to have y_values as it's parameter because
x_axis only cares about y_values.