Enable serialising empty string as object values

[georgek]

I find it useful to be able to handle empty strings in objects. I'm not aware of any reason to not support it.

[pbeshai]

For now, I'd recommend just creating your own param type and using it instead of the default if you want this behavior.

[georgek]

Is there any reason not to support it? With the current behaviour it's essentially required to remove keys whenever the value is an empty string. If not, there is very strange behaviour because an object {key: ""} will deserialise as {key: undefined}. If we allow empty strings then users can still remove the key if they wish, but the above object will still deserialise properly.

[pbeshai]

The main problem is its a breaking change, but we can just version it appropriately. I think you're right we should allow it. Can you add a test for this situation?

[georgek]

I've added some tests and also some for strings with hyphens in.

[pbeshai]

Thanks!

[pbeshai]

In v0.3.0