cbor serialize for float not match for CBOR specification

I use rust to impl IPFS, and now, I meet a problem in CBOR serialize.

this project use cbor serialize/deserialize lib is `github.com/polydawn/refmt`
but I think this CBOR implementation not match to specification for float number.

in specification:[ https://tools.ietf.org/html/rfc7049#section-2.3](https://tools.ietf.org/html/rfc7049#section-2.3)
different float would have different serialize.
For example for float16, float32, float64, etc...

but this lib would not recognition different float, it handle all float number for float64 type.
e.g.
```go
func TestFloat(t *testing.T) {
m := 1.5 // this float is float16 in fact.
//data, err := DumpObject(m)
data, err := marshaller.Marshal(m) // this would treat 1.5 as float64
fmt.Println(data, err)
// result is [251 63 248 0 0 0 0 0 0] , serialized by type float64
}
```

In rust, I use the library: https://github.com/pyfisch/cbor
In this implementation, it would handle well for float type:
```rust

fn test_cbor() {
let s = serde_cbor::to_vec(&1.5).unwrap();
println!("{:?}", s);
// result is [249, 62, 0], serialized by type float16
}
```
it implemention is like:
https://github.com/pyfisch/cbor/blob/7d1d6d31eb3620add0b7ed5fc9bc3ff42ba4a532/src/ser.rs#L334-L342
when handle float64, it would judge if it could be handled by float32.
and in float32:
https://github.com/pyfisch/cbor/blob/7d1d6d31eb3620add0b7ed5fc9bc3ff42ba4a532/src/ser.rs#L311-L324
it would handle type float16.

However I test CBOR library in python and js version, they all not match to the CBOR specification
(I choose test library from here https://cbor.io/impls.html)

So I'm confused for this. The cbor serialize would effect the cid, if not match the CBOR specification, it would cause chaos!