Change chain_id from u8 to u32

[tritone11]

chain_id as u8 make this library unsuable for all chains with a chain_id higher than 255

For example, private chains with the default chain id (1337) or the Görli testnet (6284)

This should be set as a u32, as the Stureby testnet for Constantinople has a chain id of 314158 as specified in the EIP155 implementation

[synlestidae]

Thanks for bringing it to my attention.

Is there a specified upper bound on the value of CHAIN_ID? In case u32 is not future proof

[tritone11]

@synlestidae as cited here, it is defined in geth as a BigInt, so the upper bound would be architecture dependent. It could be a u64

[reuvenpo]

I want to bump this as I'm trying to use this crate and I need to use these sorts of high chain ids, so I'm bumping this thread.

Also, according to this yet-unmerged PR on rust-web3 it can be a u64.

[synlestidae]

This change should be straightforward. I've scheduled myself some time to get it released this weekend.

[reuvenpo]

Awesome! We really appreciate it! :)

[synlestidae]

Closing this issue thanks to @Cashmaney's changes in #15