Use raise instead of fail in rescue statements

lib/producer/core/env.rb

@@ -24,7 +24,7 @@ module Producer
       def [](*args)
         @registry.fetch *args
       rescue KeyError
-        fail RegistryKeyError, args.first.inspect
+        raise RegistryKeyError, args.first.inspect
       end
       alias get []
 

lib/producer/core/recipe/file_evaluator.rb

@@ -8,7 +8,7 @@ module Producer
             begin
               Recipe.new(env).tap { |o| o.instance_eval content, file_path }
             rescue Exception => e
-              fail RecipeEvaluationError, e.message, [
+              raise RecipeEvaluationError, e.message, [
                 '%s (recipe)' % file_path,
                 *e.backtrace
               ]