add small refactors

Author: manuca

lib/skunk/cli/options.rb

@@ -20,8 +20,10 @@ def parse
         self
       end
 
+      # :reek:NilCheck
       def output_stream
-        @argv_options.output_filename.nil? ? $stdout : File.open(@argv_options.output_filename, "w")
+        output_filename = @argv_options.output_filename
+        output_filename.nil? ? $stdout : File.open(output_filename, "w")
       end
 
       # :reek:NilCheck

lib/skunk/cli/options/argv.rb

@@ -9,7 +9,7 @@ class Options
       # Extends RubyCritic::Cli::Options::Argv to parse a subset of the
       # parameters accepted by RubyCritic
       class Argv < RubyCritic::Cli::Options::Argv
-        attr_accessor :output_filename
+        attr_reader :output_filename
 
         def initialize(argv)
           super