InfStepRange should not be OrdinalRange #207
Description
By definition, OrdinalRange is only for discrete type and the step must be multiples of one.
For reference,
julia> typeof(1.0:5.0)
StepRangeLen{Float64, Base.TwicePrecision{Float64}, Base.TwicePrecision{Float64}, Int64}
julia> typeof(1.0:5.0) |> supertype
AbstractRange{Float64}
julia> typeof(1:5) |> supertype |> supertype
OrdinalRange{Int64, Int64}
julia> typeof(1:5) |> supertype |> supertype |> supertype
AbstractRange{Int64}