Fix: eof error handling when decoding in CborCodec

[sandreae]

Closes: #6

• return when decoding is eof and don't advance the buffer
• tests for this and other error cases
• update CHANGLOG

[mxinden]

Again, thank you for the work here. I have one more suggestion. Otherwise this is good to go.

Related, the other Codec implementations in this crate face the same issue. In case you are interested, I would very much appreciate fixes for those as well. No worries if not.

asynchronous-codec/src/codec/json.rs

Lines 117 to 131 in 43338f6

	// Attempt to fetch an item and generate response
	let res = match iter.next() {
	Some(Ok(v)) => Ok(Some(v)),
	Some(Err(ref e)) if e.is_eof() => Ok(None),
	Some(Err(e)) => Err(e.into()),
	None => Ok(None),
	};
	// Update offset from iterator
	let offset = iter.byte_offset();
	// Advance buffer
	buf.advance(offset);
	res

[sandreae]

Related, the other Codec implementations in this crate face the same issue. In case you are interested, I would very much appreciate fixes for those as well. No worries if not.

Happy to add this too 👍

[sandreae]

@mxinden thanks for your feedback, think this is ready to go now.

[mxinden]

Again, well done. Thank you.

[mxinden]

Suggested change

	## [0.6.2] - unreleased
	## [0.6.2]

[mxinden]

Suggested change

	- Error handling in `CborCodec` and `JsonCodec` `decode` [#7](https://github.com/mxinden/asynchronous-codec/pull/7)
	- Error handling in `CborCodec` and `JsonCodec` `decode`, more specifically not advancing the data buffer on partial decoding. See [#7](https://github.com/mxinden/asynchronous-codec/pull/7) for details.

[mxinden]

I was not able to accept the above suggestions, thus merged through #8. Attribution should still be tracked for your work.

[mxinden]

Tagged and published.

[sandreae]

Tagged and published.

Great, thanks!