Release 1.6.6

Changes since 1.6.5:
 - Fixed a bug that would raise a 404 error where a 401 error would be more suitable.
 - Added locks to prevent multiple backup tasks with the same file from running concurrently.
 - Added a task to periodically finalize incomplete builds.
 - Show column in build admin for "processed" builds

version.txt

@@ -1 +1 @@
-1.6.5
+1.6.6