clean up unnecessary usage of the six library (awx only supports py3)

awx/main/models/inventory.py

@@ -9,7 +9,6 @@ import logging
 import re
 import copy
 import os.path
-import six
 from urllib.parse import urljoin
 
 # Django
@@ -1356,7 +1355,7 @@ class InventorySourceOptions(BaseModel):
     source_vars_dict = VarsDictProperty('source_vars')
 
     def clean_instance_filters(self):
-        instance_filters = six.text_type(self.instance_filters or '')
+        instance_filters = str(self.instance_filters or '')
         if self.source == 'ec2':
             invalid_filters = []
             instance_filter_re = re.compile(r'^((tag:.+)|([a-z][a-z\.-]*[a-z]))=.*$')
@@ -1382,7 +1381,7 @@ class InventorySourceOptions(BaseModel):
             return ''
 
     def clean_group_by(self):
-        group_by = six.text_type(self.group_by or '')
+        group_by = str(self.group_by or '')
         if self.source == 'ec2':
             get_choices = getattr(self, 'get_%s_group_by_choices' % self.source)
             valid_choices = [x[0] for x in get_choices()]
@@ -1539,7 +1538,7 @@ class InventorySource(UnifiedJobTemplate, InventorySourceOptions, RelatedJobsMix
             if '_eager_fields' not in kwargs:
                 kwargs['_eager_fields'] = {}
             if 'name' not in kwargs['_eager_fields']:
-                name = six.text_type('{} - {}').format(self.inventory.name, self.name)
+                name = '{} - {}'.format(self.inventory.name, self.name)
                 name_field = self._meta.get_field('name')
                 if len(name) > name_field.max_length:
                     name = name[:name_field.max_length]