Add rake console task

Author: aredondo

Rakefile

@@ -4,3 +4,15 @@ require 'rspec/core/rake_task'
 task default: :spec
 
 RSpec::Core::RakeTask.new
+
+task :environment do
+  require_relative 'lib/monetize'
+end
+
+desc 'Start a console with library loaded'
+task console: :environment do
+  require 'irb'
+  require 'irb/completion'
+  ARGV.clear
+  IRB.start
+end