Fixed Segwit links
Fixed Segwit links

The links were redirecting to 404 - I've modified them so they adhere to the beginning of the respective Segwit unit tests.
BitGo/bitcoinjs-lib,bitcoinjs/bitcoinjs-lib,UdjinM6/bitcoinjs-lib-dash,visvirial/bitcoinjs-lib,BitGo/bitcoinjs-lib,junderw/bitcoinjs-lib,bitcoinjs/bitcoinjs-lib,visvirial/bitcoinjs-lib,junderw/bitcoinjs-lib