Added default step-size and tolerance to gradient descent
Added default step-size and tolerance to gradient descent

JuliaPackageMirrors/Optim.jl,yuyichao/Optim.jl,pkofod/Optim.jl,yuyichao/Optim.jl,KristofferC/Optim.jl,zhmz90/Optim.jl,KristofferC/Optim.jl,zhmz90/Optim.jl,JuliaPackageMirrors/Optim.jl,matthieugomez/Optim.jl,pkofod/Optim.jl,matthieugomez/Optim.jl