Bugfixes
Calculate correct phi_0 values
#118
#119
Correctly handle dphi0_previous in InitialConstantChange
#122
JuliaNLSolvers/Optim.jl#613
Calculate correct phi_0 values
#118
#119
Correctly handle dphi0_previous in InitialConstantChange
#122
JuliaNLSolvers/Optim.jl#613