message: Remove dependency on six
  Summary:
  This dependency makes it impossible to add this directory to your PYTHONPATH and import dex (with the dependency you need to make sure you have six installed too).
  The logic is maintained before and after
diff: @@ -22,7 +22,6 @@ import operator
  import optparse
  import os
  import re
  -import six
  import string
  import sys
  @@ -1448,7 +1447,7 @@ class File:
  self.debug_info_items = list()
  for i in range(size):
  item = debug_info_item(self.data)
  - _ = item.get_ops(reset_offset=False)
  + item.get_ops(reset_offset=False)
  self.debug_info_items.append(item)
  self.debug_info_items_total_size = self.data.tell() - offset
  self.data.pop_offset_and_seek()
  @@ -1456,7 +1455,7 @@ class File:
  def find_class(self, class_ref):
  class_idx = class_ref
  - if isinstance(class_ref, six.string_types):
  + if isinstance(class_ref, str):
  # Make sure the string is in 'L' <classname-with-slashes> ';'
  class_mangled = mangle_classname(class_ref)
  class_str_idx = self.find_string_idx(class_mangled)
  