Fatal errors should not be logged as warnings

[tazjin]

This was easy to miss on first run:

INFO[03-17|13:54:08] All inputs acquired... starting assembly 
INFO[03-17|13:54:13] Assembly complete!                       elapsed=4.623
INFO[03-17|13:54:13] Beginning execution! 
INFO[03-17|13:54:13] Execution done!                          elapsed=0.015
WARN[03-17|13:54:13] Container start failed: [8] System error: fork/exec /proc/self/exe: operation not permitted runc-time=2017-03-17T13:54:13Z runc-level=fatal
INFO[03-17|13:54:13] Have 1 outputs to be scanned 
INFO[03-17|13:54:13] Starting scan                            output=executable type=tar
INFO[03-17|13:54:13] Finished scan                            output=executable type=tar elapsed=0.000
INFO[03-17|13:54:13] Output 1/1 saved 
{
	"UID": "bbe8r1k6-vsm9rv60-drddxsrn",
	"results": {
		"$exitcode": {
			"hash": "1",
			"type": "exitcode"
		},
		"executable": {
			"hash": "",
			"type": "tar"
		}
	},
	"when": "2017-03-17T13:54:13Z"
}
job finished with non-zero exit status 1

I'm assuming the cause is that warning, which is then in fact an error and not a warning.

[warpfork]

This should be fixed now! Thanks for pointing it out.