update chain_id to latest, add tx builder option to specify chain_id

[zone117x]

Description

Core-node master just updated the chain_id value to new constant. This PR updates the constant, and also adds chainId as a configurable value in the transaction builder functions.

For details refer to issue #123

Type of Change

• [x] New feature
• [x] Bug fix
• [ ] API reference/documentation update
• [ ] Other

Checklist

• [x] Code is commented where needed
• [x] Unit test coverage for new or modified code paths
• [x] npm run test passes
• [ ] Changelog is updated
• [x] Tag 1 of @yknl, @zone117x, @reedrosenbluth for review

[zone117x]

note: using this branch with latest core-node and am able to generate valid transactions