Update gitignore #251

Job	Run time
run-benchmark (nlp)	1m 49s
run-benchmark (file-enc)	1m 21s
run-benchmark (unix50)	3m 31s
run-benchmark (log-analysis)	4m 9s
run-benchmark (max-temp)	26m 43s
run-benchmark (uniq-ips)	13s
run-benchmark (media-conv)	3m 28s
run-benchmark (sklearn)	2m 6s
run-benchmark (covid-mts)	44s
run-benchmark (riker)	9m 34s
run-benchmark (oneliners)	37s
run-benchmark (web-index)	1m 31s
run-benchmark (vps-audit)	7m 22s
run-benchmark (vps-audit-negate)	3m 13s
run-benchmark (makeself)	1m 25s
	1h 7m 46s

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