fix serialize bug in #344

[ekinakyurek]

After Julia fixed deepcopy bug, I fix our serialization bug too.

[denizyuret]

#425 ve #433 icin simdi fail eden duzeltmeden sonra gecen test lazim...

[ekinakyurek]

I merged with #425 and added the tests that fails before

[ekinakyurek]

@denizyuret could you try below snippet by activating this project https://github.com/ekinakyurek/Morse.jl/tree/predict on a cpu only machine, which requires internet connection to download the saved model:

julia> using Knet, KnetLayers , Morse
julia> model, vocabulary, parser = trained(MorseModel, TRDataSet, vers="2018");
julia> predictions = model("annem sana yardım edemez .", v=vocabulary, p=parser)

I'm getting assertion error on size of hidden states, whereas I don't get any error on a GPU machine.

[denizyuret]

```julia
julia> using Knet, KnetLayers , Morse
julia> model, vocabulary, parser = trained(MorseModel, TRDataSet, vers="2018");
julia> predictions = model("annem sana yardım edemez .", v=vocabulary, p=parser)

You had a 2-D hidden state instead of 3-D. I modified the code so the assertion ignores trailing 1 dimensions.