Add Crono.config

spec/config_spec.rb

@@ -3,7 +3,7 @@ require "spec_helper"
 describe Crono::Config do
   describe "#initialize" do
     it "should initialize schedule" do
-      @config = Crono::Config.instance
+      @config = Crono.config
       expect(@config.schedule).to be_a(Crono::Schedule)
     end
   end