resistor-color-duo: Update exercise to 2.1.0

exercises/resistor-color-duo/.meta/solutions/resistor_color_duo.rb

@@ -14,6 +14,7 @@ module ResistorColorDuo
 
   def self.value(color_bands)
     color_bands
+      .first(2)
       .map { |color| COLORS.index(color) }
       .join
       .to_i

exercises/resistor-color-duo/README.md

@@ -4,22 +4,17 @@ If you want to build something using a Raspberry Pi, you'll probably use _resist
 
 * Each resistor has a resistance value.
 * Resistors are small - so small in fact that if you printed the resistance value on them, it would be hard to read.
-To get around this problem, manufacturers print color-coded bands onto the resistors to denote their resistance values. Each band acts as a digit of a number. For example, if they printed a brown band (value 1) followed by a green band (value 5), it would translate to the number 15.
-
-In this exercise, you are going to create a helpful program so that you don't have to remember the values of the bands. The program will take two colors as input, and output the correct number.
-
-The band colors are encoded as follows:
-
-- Black: 0
-- Brown: 1
-- Red: 2
-- Orange: 3
-- Yellow: 4
-- Green: 5
-- Blue: 6
-- Violet: 7
-- Grey: 8
-- White: 9
+To get around this problem, manufacturers print color-coded bands onto the resistors to denote their resistance values. Each band has a position and a numeric value. For example, if they printed a brown band (value 1) followed by a green band (value 5), it would translate to the number 15.
+
+In this exercise you are going to create a helpful program so that you don't have to remember the values of the bands. The program will take color names as input and output a two digit number, even if the input is more than two colors!
+
+The colors are mapped to the numbers from 0 to 9 in the sequence:
+Black - Brown - Red - Orange - Yellow - Green - Blue - Violet - Grey - White
+
+From the example above:
+brown-green should return 15
+brown-green-violet should return 15 too, ignoring the third color.
+
 
 * * * *
 

exercises/resistor-color-duo/resistor_color_duo_test.rb

@@ -1,7 +1,7 @@
 require 'minitest/autorun'
 require_relative 'resistor_color_duo'
 
-# Common test data version: 2.0.0 8b44ce1
+# Common test data version: 2.1.0 00dda3a
 class ResistorColorDuoTest < Minitest::Test
   def test_brown_and_black
     # skip
@@ -22,4 +22,9 @@ def test_orange_and_orange
     skip
     assert_equal 33, ResistorColorDuo.value(["orange", "orange"])
   end
+
+  def test_ignore_additional_colors
+    skip
+    assert_equal 51, ResistorColorDuo.value(["green", "brown", "orange"])
+  end
 end