fishers_exact

fishers_exact is used at run time in 4 crates (of which 2 optionally).

Depender (with downloads and own rev deps)			fishers_exact version
		rustynuc		^1.0.1
		csv_fish		^1.0
150		haptk	optional	^1.0.1
	1	wordle_rs	optional	^1.0.1