refactor(abstract-utxo): use @bitgo/utxo-core

Ticket: BTC-1821

Author: OttoAllmendinger

modules/abstract-utxo/.eslintrc.js

@@ -2,5 +2,6 @@ module.exports = {
   extends: ['../../.eslintrc.json'],
   rules: {
     'import/order': ['error', { 'newlines-between': 'always' }],
+    'import/no-internal-modules': 'off',
   },
 };

modules/abstract-utxo/package.json

@@ -53,7 +53,6 @@
     "@types/lodash": "^4.14.121",
     "@types/superagent": "4.1.15",
     "bignumber.js": "^9.0.2",
-    "bip174": "npm:@bitgo-forks/[email protected]",
     "bitcoinjs-message": "npm:@bitgo-forks/[email protected]",
     "bluebird": "^3.5.3",
     "debug": "^3.1.0",