workaround for JuliaLang/julia#8935
tighten performance claim
links to KNITRO
try to fix appveyor (#303)
fix #301
parametrize JuMPArray on dimension for tighter method signatures, fixes #299
Merge pull request #306 from JuliaOpt/fix301

fix #301
remove deprecated load_model_only keyword
Refactor tests to use all solvers and FactCheck.jl