Added mixtures JSON files

Signed-off-by: Ian Bell <ian.h.bell@gmail.com>
Fixed genetic solver

Signed-off-by: Ian Bell <ian.h.bell@gmail.com>
Prep for 4.0

Signed-off-by: Ian Bell <ian.h.bell@gmail.com>
Merge branch 'master' of https://github.com/ibell/coolprop

Conflicts:
	CoolProp/gitrevision.h