Remove unneded parser extension

config/flay.yml

@@ -1,3 +1,3 @@
 ---
 threshold: 18
-total_score: 1120
+total_score: 1118

lib/mutant.rb

@@ -7,7 +7,6 @@ require 'equalizer'
 require 'digest/sha1'
 require 'parser'
 require 'parser/current'
-require 'parser_extensions'
 require 'unparser'
 require 'ice_nine'
 require 'diff/lcs'

lib/parser_extensions.rb

@@ -1,25 +0,0 @@
-# Monkeypatch to silence warnings in parser
-#
-# Will be removed once https://github.com/whitequark/parser/issues/145 is solved.
-
-# Parser namespace
-module Parser
-  # Monkeypatched lexer
-  class Lexer
-
-    # Return new lexer
-    #
-    # @return [Lexer]
-    #
-    # @api private
-    #
-    def self.new(*arguments)
-      super.tap do |instance|
-        instance.instance_eval do
-          @force_utf32 = false
-        end
-      end
-    end
-
-  end # Lexer
-end # Parser