add tests for generating blocks with a non-empty transaction pool
add tests for generating blocks with a non-empty transaction pool

MrStrong/Sia,MrStrong/Sia,ericflo/Sia,johnathanhowell/Sia,kustomzone/Sia,mnsl/Sia,NebulousLabs/Sia,mtlynch/Sia,ChrisSchinnerl/Sia,mnsl/Sia,mtlynch/Sia,NebulousLabs/Sia,mharkus/Sia,mharkus/Sia,ericflo/Sia,ChrisSchinnerl/Sia,Mingling94/Sia,rivine/rivine,cyrozap/Sia,rivine/rivine