fix(config): deprecate the report_as field for challenges

This was a bad idea when it was added and it is irresponsible to
continue to have it. It causes more UX problems than it fixes with
slight of hand.

Closes: #1310
Closes: #1307
Signed-off-by: Xe Iaso <me@xeiaso.net>

lib/challenge/proofofwork/proofofwork_test.go

@@ -36,7 +36,6 @@ func TestBasic(t *testing.T) {
 		Challenge: &config.ChallengeRules{
 			Algorithm:  "fast",
 			Difficulty: 0,
-			ReportAs:   0,
 		},
 	}
 	const challengeStr = "hunter"