Use Django's get_random_secret_key instead of own code.

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

mayan/apps/common/management/commands/createsettings.py

@@ -4,7 +4,7 @@ import os
 
 from django.conf import settings
 from django.core import management
-from django.utils.crypto import get_random_string
+from django.core.management.utils import get_random_secret_key
 
 from ...settings import setting_local_settings_filename
 
@@ -14,11 +14,6 @@ from .literals import SETTING_FILE_TEMPLATE
 class Command(management.BaseCommand):
     help = 'Creates a local settings file with a random secret key.'
 
-    @staticmethod
-    def _generate_secret_key():
-        chars = 'abcdefghijklmnopqrstuvwxyz0123456789!@#$%^&*(-_=+)'
-        return get_random_string(50, chars)
-
     def handle(self, *args, **options):
         path = os.path.join(settings.BASE_DIR, 'settings', '{}.py'.format(setting_local_settings_filename.value))
         if os.path.exists(path):
@@ -26,5 +21,5 @@ class Command(management.BaseCommand):
         else:
             with open(path, 'w+') as file_object:
                 file_object.write(
-                    SETTING_FILE_TEMPLATE.format(Command._generate_secret_key())
+                    SETTING_FILE_TEMPLATE.format(get_random_secret_key())
                 )