EDF export error

[a-cakir]

Putting this here so I dont forget to come back to it.

Running a signal with NaNs in them lead to the error below:

Got exception outside of a @test
  InexactError: trunc(Int16, NaN)
  Stacktrace:
    [1] trunc
      @ ./float.jl:760 [inlined]
    [2] round
      @ ./float.jl:359 [inlined]
    [3] encode_sample
      @ ~/.julia/packages/Onda/RFXm5/src/samples.jl:183 [inlined]
    [4] encode_sample
      @ ~/.julia/packages/Onda/RFXm5/src/samples.jl:180 [inlined]
    [5] _broadcast_getindex_evalf
      @ ./broadcast.jl:670 [inlined]
    [6] _broadcast_getindex
      @ ./broadcast.jl:653 [inlined]
    [7] getindex
      @ ./broadcast.jl:597 [inlined]
    [8] macro expansion
      @ ./broadcast.jl:961 [inlined]
    [9] macro expansion
      @ ./simdloop.jl:77 [inlined]
   [10] copyto!
      @ ./broadcast.jl:960 [inlined]
   [11] copyto!
      @ ./broadcast.jl:913 [inlined]
   [12] materialize!
      @ ./broadcast.jl:871 [inlined]
   [13] materialize!(dest::Matrix{Int16}, bc::Base.Broadcast.Broadcasted{Base.Broadcast.DefaultArrayStyle{2}, Nothing, typeof(Onda.encode_sample), Tuple{Base.RefValue{Type{Int16}}, Float64, Float64, Matrix{Float64}}})
      @ Base.Broadcast ./broadcast.jl:868
   [14] broadcast!(::typeof(Onda.encode_sample), ::Matrix{Int16}, ::Type, ::Float64, ::Float64, ::Matrix{Float64})
      @ Base.Broadcast ./broadcast.jl:837
   [15] encode!
      @ ~/.julia/packages/Onda/RFXm5/src/samples.jl:281 [inlined]
   [16] encode(::Type{Int16}, sample_resolution_in_unit::Float64, sample_offset_in_unit::Float64, sample_data::Matrix{Float64}, dither_storage::Nothing)
      @ Onda ~/.julia/packages/Onda/RFXm5/src/samples.jl:243
   [17] encode(samples::Samples{Matrix{Float64}}, dither_storage::Nothing)
      @ Onda ~/.julia/packages/Onda/RFXm5/src/samples.jl:313
   [18] encode
      @ ~/.julia/packages/Onda/RFXm5/src/samples.jl:312 [inlined]
   [19] reencode_samples(samples::Samples{Matrix{Float64}}, sample_type::Type{Int16})
      @ OndaEDF ~/.julia/packages/OndaEDF/0ybPL/src/export_edf.jl:177
   [20] onda_samples_to_edf_signals(onda_samples::Vector{Samples}, seconds_per_record::Float64)
      @ OndaEDF ~/.julia/packages/OndaEDF/0ybPL/src/export_edf.jl:184