title: Suppress warning output on manage.py dumpdata?
body: <p>I'm using django's dumpdata and loaddata commands to facilitate  some data exports.  However I currently have some unresolved deprecation warnings and so when I write the output of dumpdata to a file the warnings end up at the top of the file and I must manually clean up the dump files every time.  Is there any way to suppress or avoid the warnings do that the output of dumpdata is legitimate json without having to manually remove the warning text each time?</p>