Error using PECE with system with parameters

[jClugstor]

When trying to solve an FODE system with parameters an error occurs

`using FractionalDiffEq, Plots
plotlyjs()

function ChenSystem(du,u,p,t)
α, b, γ = p

x = u[1]
y = u[2]
z = u[3]

dx = α*(y - x)
dy = (γ - α)*x - x*z + γ*y
dz = x*y - b*z

du[1] = dx
du[2] = dy
du[3] = dz

end

prob = FODESystem(ChenSystem,qrow,y0,tspan,pars)
Ys = solve(prob, stepsize, PECE())
`
I think this is because PIPECE wasn't changed to allow for systems with separate parameters. Also noticed that PIPECE wasn't returning an FODESolution. I have a fix and will submit a pull request.