MatlabExecutionResult: Serialization of some primitives will change the type

[TomasSkotare]

If a single value is returned, the json_tricks library will change the type of the data from for example numpy.uint16 to the Python int type, due to some issues with the default json library.

See this proposed change for json_tricks 4.0:
mverleg/pyjson_tricks#99

This means, in effect, that verify_serialization on the MatlabExecutionResult will not produce the exact same type (but the same value) after loading and saving the data.

For now, we'll leave this and hope the new version solves the issue, although I must stress that the value itself is not lost, just the type it is represented by.

[TomasSkotare]

Added a workaround for this, we'll see how it pans out.