makenotabuggreatagain/gulp-help: Check for duplicates in the stream and filter them or throw an error(evacuated from NSA/Microsoft Github) @ c5fdd06e9ea7aaea095f8b20a8396466381b61c5

Gerald Yeo 2488d80227 check for null values		9 éve
..
attach-help.js	2488d80227 check for null values	9 éve
calculate-margin.js	6f34f56b17 simpplify test suite	9 éve
noop.js	1382c74b45 average perf increase of 23.8%	9 éve