Removed six as a dependency

Changed logic for checking if run_command argument is a list. Fixed
tests and refactoring save_save() method in cd32 module.

fs_uae_wrapper/cd32.py

@@ -165,9 +165,8 @@ class CD32(object):
         if os.path.exists(self.save_filename):
             os.unlink(self.save_filename)
 
-        code = utils.run_command(['7z', 'a', self.save_filename,
-                                  os.path.join(self.dir, 'fs-uae-save')])
-        if code != 0:
+        if not utils.run_command(['7z', 'a', self.save_filename,
+                                  os.path.join(self.dir, 'fs-uae-save')]):
             sys.stderr.write('Error: archiving save state failed\n')
             return False
 

fs_uae_wrapper/utils.py

@@ -3,7 +3,6 @@ Misc utilities
 """
 from distutils import spawn
 import os
-import six
 import subprocess
 import sys
 try:
@@ -109,11 +108,12 @@ def extract_archive(arch_name, show_gui_message, message_text):
 def run_command(cmd):
     """
     Run provided command. Return true if command execution returns zero exit
-    code, false otherwise. If cmd is a string, there would be an attempt to
-    split it up for subprocess call method.
+    code, false otherwise. If cmd is not a list, there would be an attempt to
+    split it up for subprocess call method. May throw exception if cmd is not
+    a list neither a string.
     """
 
-    if isinstance(six.text_type(cmd), six.string_types):
+    if not isinstance(cmd, list):
         cmd = cmd.split()
 
     code = subprocess.call(cmd)