Fixed #19397 -- Crash on binary files in project templates.

Thanks gw 2012 at tnode com for the report.

django/core/management/templates.py

@@ -8,8 +8,6 @@
 import stat
 import sys
 import tempfile
-import codecs
-
 try:
     from urllib.request import urlretrieve
 except ImportError:     # Python 2
@@ -156,12 +154,14 @@ def handle(self, app_or_project, name, target=None, **options):
 
                 # Only render the Python files, as we don't want to
                 # accidentally render Django templates files
-                with codecs.open(old_path, 'r', 'utf-8') as template_file:
+                with open(old_path, 'rb') as template_file:
                     content = template_file.read()
                 if filename.endswith(extensions) or filename in extra_files:
+                    content = content.decode('utf-8')
                     template = Template(content)
                     content = template.render(context)
-                with codecs.open(new_path, 'w', 'utf-8') as new_file:
+                    content = content.encode('utf-8')
+                with open(new_path, 'wb') as new_file:
                     new_file.write(content)
 
                 if self.verbosity >= 2: