Ensure robustness to integer vs. floating-point numbers

[ajkeller34]

e.g. sometimes CellReference(c, Point(0,0)) will fail with an InexactError.

[ajkeller34]

Minimal reproducible example:

julia> c2 = Cell("c2", nm);

julia> render!(c2, Rectangle(1μm, 1μm));

julia> const c2ref = CellReference(c2, Point(0μm,0μm)); # 0μm (not 0.0μm) required to cause the error

julia> c = Cell("c", nm);

julia> ro = Path(μm, α0 = 180°); # nonzero angle is also important to cause the error

julia> straight!(ro, 10μm, Paths.Trace(1μm));

julia> attach!(ro, c2ref, pathlength(ro));

julia> render!(c, ro)
ERROR: InexactError()
Stacktrace:
 [1] convert(::Type{Int64}, ::Float64) at ./float.jl:679
 [2] convert at /Users/ajkeller/.julia/v0.6/Unitful/src/conversion.jl:91 [inlined]
 [3] Devices.Points.Point{Quantity{Int64, Dimensions:{𝐋}, Units:{μm}}}(::Quantity{Float64, Dimensions:{𝐋}, Units:{μm}}, ::Quantity{Float64, Dimensions:{𝐋}, Units:{μm}}) at /Users/ajkeller/.julia/v0.6/Devices/src/points.jl:20
 [4] convert(::Type{Devices.Points.Point{Quantity{Int64, Dimensions:{𝐋}, Units:{μm}}}}, ::Devices.Points.Point{Quantity{Float64, Dimensions:{𝐋}, Units:{μm}}}) at /Users/ajkeller/.julia/v0.6/StaticArrays/src/convert.jl:7
 [5] #render!#56(::Array{Any,1}, ::Function, ::Devices.Cells.Cell{Quantity{Float64, Dimensions:{𝐋}, Units:{nm}},Devices.GDSMeta}, ::Devices.Paths.Straight{Quantity{Float64, Dimensions:{𝐋}, Units:{μm}}}, ::Devices.Paths.DecoratedStyle{Quantity{Float64, Dimensions:{𝐋}, Units:{μm}}}, ::Devices.GDSMeta) at /Users/ajkeller/.julia/v0.6/Devices/src/render/decorated.jl:19
 [6] render!(::Devices.Cells.Cell{Quantity{Float64, Dimensions:{𝐋}, Units:{nm}},Devices.GDSMeta}, ::Devices.Paths.Straight{Quantity{Float64, Dimensions:{𝐋}, Units:{μm}}}, ::Devices.Paths.DecoratedStyle{Quantity{Float64, Dimensions:{𝐋}, Units:{μm}}}, ::Devices.GDSMeta) at /Users/ajkeller/.julia/v0.6/Devices/src/render/decorated.jl:11
 [7] #render!#7(::Array{Any,1}, ::Function, ::Devices.Cells.Cell{Quantity{Float64, Dimensions:{𝐋}, Units:{nm}},Devices.GDSMeta}, ::Devices.Paths.Path{Quantity{Float64, Dimensions:{𝐋}, Units:{μm}}}, ::Devices.GDSMeta) at /Users/ajkeller/.julia/v0.6/Devices/src/render/paths.jl:24
 [8] render!(::Devices.Cells.Cell{Quantity{Float64, Dimensions:{𝐋}, Units:{nm}},Devices.GDSMeta}, ::Devices.Paths.Path{Quantity{Float64, Dimensions:{𝐋}, Units:{μm}}}) at /Users/ajkeller/.julia/v0.6/Devices/src/render/paths.jl:6

[ajkeller34]

Fixed. Problem was likely that render! attempted to add a fraction of a micron to the origin of the cell reference, which had integer micron coordinates. Now references and arrays always have floating-point coordinates.