add a new cms ENV configuration to use a slow upload file handler to help test…

add a new cms ENV configuration to use a slow upload file handler to help test progress bars in uploads

cms/djangoapps/contentstore/debug_file_uploader.py

+from django.core.files.uploadhandler import FileUploadHandler
+import time
+
+
+class DebugFileUploader(FileUploadHandler):
+    def receive_data_chunk(self, raw_data, start):
+        time.sleep(1)
+        return raw_data
+
+    def file_complete(self, file_size):
+        return None

cms/envs/debug_upload.py

+from .dev import *
+
+FILE_UPLOAD_HANDLERS = (
+    'contentstore.debug_file_uploader.DebugFileUploader',
+    'django.core.files.uploadhandler.MemoryFileUploadHandler',
+    'django.core.files.uploadhandler.TemporaryFileUploadHandler',
+)

cms/envs/dev.py

@@ -36,6 +36,7 @@ MODULESTORE = {
     }
 }
 
+
 # cdodge: This is the specifier for the MongoDB (using GridFS) backed static content store
 # This is for static content for courseware, not system static content (e.g. javascript, css, edX branding, etc)
 CONTENTSTORE = {