Change the default ShadedAscii style to relative

I only changed it in the executable :(

honeybii.gemspec

@@ -1,7 +1,7 @@
 Gem::Specification.new do |s|
   s.name = 'honeybii'
-  s.version = '2.0.3'
-  s.date = '2014-04-12'
+  s.version = '2.0.4'
+  s.date = '2014-04-13'
   s.executables << 'honeybii'
   s.add_runtime_dependency 'rmagick', ['~> 2.13', '>= 2.13.2']
   s.files = ['lib/honeybii.rb', 'lib/honeybii/ascii_image.rb', 'lib/honeybii/shaded_ascii.rb']

lib/honeybii/shaded_ascii.rb

@@ -1,6 +1,7 @@
 class ShadedAscii < AsciiImage
   class << self
     attr_accessor :gradients
+    attr_accessor :styles
   end
 
   @gradients = [
@@ -9,9 +10,11 @@ class << self
     ['#', '+', ':', ' ', ' '],
     ['0', '1', ' ', ' '],
   ]
+  @styles = [ 'relative', 'one_to_one' ]
 
-  def initialize(image_filename, point_size = 12, gradient: 0, style: 'one_to_one')
+  def initialize(image_filename, point_size = 12, gradient: 0, style: 'relative')
     super image_filename, point_size
+    raise ArgumentError, "style must be one of the following: #{ShadedAscii.styles}" unless ShadedAscii.styles.include? style
     @gradient = ShadedAscii.gradients[gradient]
     @style = style
     to_ascii!

test/test_shaded_ascii.rb

@@ -34,8 +34,8 @@ def test_image_can_use_different_gradients
   end
 
   def test_intensity_range_creates_different_ascii
-    shaded_1_to_1 = ShadedAscii.new('test/images/flower_bee.jpg', 14, style: '1_to_1')
-    shaded_relative = ShadedAscii.new('test/images/flower_bee.jpg', 14, style: 'relative')
-    refute_equal shaded_1_to_1.ascii, shaded_relative.ascii
+    shaded_relative = ShadedAscii.new('test/images/flower_bee.jpg', 14)
+    shaded_one_to_one = ShadedAscii.new('test/images/flower_bee.jpg', 14, style: 'one_to_one')
+    refute_equal shaded_one_to_one.ascii, shaded_relative.ascii
   end
 end