finish monthlyWB_summary()

[dylanbeaudette]

The function should use information about AWC, PWP, SAT to assign moisture state. It doesn't make sense for a soil series like PIERRE to have "0 dry days".

dry	moist	wet	dry_con	moist_con	wet_con	total_deficit	total_surplus	total_AET	annual_AET_PET_ratio	series
61	183	122	61	91	91	-618.64	225.14	235.36	0.28	amador
0	183	183	0	183	122	-121.66	434.66	833.34	0.87	lucy
0	152	213	0	152	152	-65.11	335.11	633.89	0.91	drummer
0	304	61	0	244	61	-223.56	25.56	407.44	0.65	pierre