examples/tsp.jl is not tested

[diam]

Bonjour,
Some months ago, I've succesfully tested tsp.jl with julia-0.3.1 and cplex or glpk (although the example is provide for gurobi).
I'm now testing the new tsp.jl exemple with the last JuMP version and julia-0.4.0 but get some error.
I saw #684, but it seems to be fixed!

Are code in the examples directory supposed to be maintained with each JuMP versions?

-- Maurice

----
Inside subtour callback
Current tour starting at city 1:
[1,2,3,1]Adding subtour elimination cut
----
ERROR: LoadError: MethodError: `isless` has no method matching isless(::JuMP.GenericAffExpr{Float64,JuMP.Variable}, ::Int64)
Closest candidates are:
  isless(!Matched::AbstractFloat, ::Real)
  isless(!Matched::ForwardDiff.ForwardDiffNumber{N,T<:Real,C}, ::Real)
  isless(!Matched::Real, ::Real)
  ...
 in subtour at /..../run_tsp_cplex_distrib_20160310.jl:212
 in lazycallback at /.../pkgs/v0.4/JuMP/src/callbacks.jl:65
...

[mlubin]

Thanks for catching this, I've fixed the example. I'll leave this issue open until we're running tsp.jl as part of the test suite.

[diam]

Thank you very much: it works (with Pkg.checkout("JuMP")).

Also, adding lines like these following ones help me switching from one solver to another one
(I'm interested if there is a better Julia way to do this).

solver = "glpk"
    if length(ARGS) > 0
        solver = lowercase(ARGS[1])
    end
    if solver == "cplex"
        using CPLEX
        getModel() = Model(solver=CplexSolver())
    elseif solver == "gurobi"
        using Gurobi
        getModel() = Model(solver=GurobiSolver())
    else # "glpk" par défaut même si solver incorrect ou inconnu
        using GLPKMathProgInterface
        getModel() = Model(solver=GLPKSolverMIP())
    end
    print("\nLoading $(solver) solver\n")