Add identify example

examples/identify/Gemfile

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+source 'https://rubygems.org'
+
+gem 'lifx', path: '../../'

examples/identify/identify.rb

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+# Identify
+#
+# This example uses a divide and conquer search algorithm to identify a light visually.
+# It will set all lights to white, then partition them by colour.
+# On each iteration, it will ask you what colour the bulb you're trying to identify is showing
+# until it narrows it down to a single bulb.
+# Please note it does not restore the light state before identification.
+
+require 'bundler'
+Bundler.require
+
+COLOURS = {
+  'red' => [0, 1, 1],
+  'yellow' => [50, 1, 1],
+  'green' => [120, 1, 1],
+  'blue' => [220, 1, 1]
+}
+
+LIFX::Config.logger = Yell.new(STDERR, :level => :error)
+c = LIFX::Client.lan
+c.discover
+5.times do
+  c.lights.refresh
+  c.flush
+  sleep 1
+  puts "Lights found: #{c.lights.count}"
+end
+
+
+def partition(list, partitions)
+  [].tap do |array|
+    list.each_slice((list.count / partitions.to_f).ceil) do |chunk|
+      array << chunk
+    end
+  end
+end
+
+lights = c.lights.to_a
+mapping = {}
+
+while lights.count > 1
+  puts "Searching through #{lights.count} lights..."
+  c.lights.set_color(LIFX::Color.white)
+  partitions = partition(lights, COLOURS.values.count)
+  COLOURS.keys.each_with_index do |color_name, index|
+    color = LIFX::Color.hsb(*COLOURS[color_name])
+    mapping[color_name] = partitions[index]
+    next if partitions[index].nil?
+    partitions[index].each do |l|
+      l.set_color(color, duration: 0)
+    end
+  end
+  puts "Waiting for flush."
+  c.flush
+  puts "What colour is the bulb you're trying to identify? (#{COLOURS.keys.join(', ')})"
+  resp = gets.strip
+  if mapping.has_key?(resp)
+    lights = mapping[resp]
+  else
+    puts "Colour not found. Iterating again"
+  end
+end
+
+if lights.count == 1
+  puts "Light identified: #{lights.first}"
+else
+  puts "No bulbs found."
+end
+
+c.flush