Hash-Chain

Hash-Chain is used at run time in 6 crates. It is a direct run-time dependency in 3 crates. It's used only as a dev dependency in 2 crates.

Depender (with downloads and own rev deps)			Hash-Chain version
290	4	ressa		^0.3
	1	ressa_r		^0.3
		cxx2flow		^0.3.2