I'm trying to get a list of deleted records through the REST API but it doesn't seem to be working.

Here is the CURL command I'm using (pretty much straight from the doc).

curl -v 'https://na30.salesforce.com/services/data/v20.0/sobjects/lead/deleted/' \
-H 'Authorization: Bearer <lots of characters>' \
-H 'X-PrettyPrint:1' \
-d 'start=2016-06-19T21:32:42.000+0000' \
-d 'end=2016-08-19T21:32:42.000+0000'

Here's the response I get:

[ {
  "errorCode" : "NOT_FOUND",
  "message" : "The requested resource does not exist"
} ]* Connection #0 to host na30.salesforce.com left intact

What should this command look like?
 

Hello,

I'm having trouble checking the challenge, I've checked other discussions and I've done exactly what others have done to pass but everytime I click check challange it gives me this error message:

Looks like something went wrong, please try again later.

I've logged out of both Developer Edition and Trailhead acc, used another new Developer Edition to redo the challenge and it gives me the same message.