Fix a few coding standards issues:

* Remove extra empty lines before private keyword usages.

  specs:

  * Fix one long line;
  * use proc keyword instead of Proc.new.

spec/producer/core/cli_spec.rb

@@ -49,7 +49,8 @@ module Producer::Core
 
     describe '#evaluate_recipe_file' do
       it 'builds a recipe' do
-        expect(Recipe).to receive(:from_file).with(arguments[1]).and_call_original
+        expect(Recipe)
+          .to receive(:from_file).with(arguments[1]).and_call_original
         cli.evaluate_recipe_file
       end