nucgen

It's used only as a dev dependency in 4 crates.

Depender (with downloads and own rev deps)			nucgen version
290		bitnuc-mismatch	dev	^0.1.1
160	2	vbinseq	dev	^0.1.2
160	2	binseq	dev	^0.1.1
140	3	bitnuc	dev	^0.1.1