Dumping Python dict yields invalid HSD

[awvwgk]

Since keys in Python dicts are case sensitive, one can easily build a dict that has no valid HSD representation. Unfortunately, this is exactly what happens with the implementation in this repo:

>>> import hsd
>>> print(hsd.dumps({'key': 0.0, 'Key': 1.0}))
key = 0.0
Key = 1.0

The preferable solution would be an exception from the serializer or a way to normalize a dict for HSD dumping.

Together with #6, the deserialization of the above HSD then yields {'key': [0.0, 1.0]}, so it cannot even be identified as invalid HSD.

[awvwgk]

Trying again with this dict

{'key': 0.0, 'Key': 1.0, ' key': -1.0, 'Key ': True}

reveals that the serializer cannot correctly cope with spaces as well.