earnerRateModel.rate()
Returns current earner rate in basis points: P1∗er1∗t−P1=P2∗er2∗t−P2
If totalActiveOwedM<=totalEarningSupply,
r2=minterRate∗totalActiveOwedM/totalEarningSupply,
Otherwise, calculates equilibrium rate
P1∗er1∗t−P1=P2∗er2∗t−P2
r2=ln(1+(P1∗er1∗t−P1)/P2),
P1=totalActiveOwedM, P2=totalEarningSupply, t=confidenceinterval
Returns min(baseEarnerRate,MULTIPLIER∗r2), where baseEarnerRate and minterRate are APY in basis points.
