Simplify internal generateKey API

src/index.js

@@ -60,7 +60,7 @@ class Vain extends Emitter {
 
 			attempts++;
 
-			keyData = generateKey({addressFormat, options, attempts});
+			keyData = generateKey({...options, addressFormat, attempts});
 			address = addressFormat.derive(keyData.publicKey);
 
 			if (address.startsWith(this.prefix)) {

src/key-formats/bip39.js

@@ -1,8 +1,8 @@
 const bip39 = require('bip39');
 const bitcoin = require('bitcoinjs-lib');
 
-const generatebip39Key = ({addressFormat, options}) => {
-	const mnemonic = bip39.generateMnemonic(options.entropy);
+const generatebip39Key = ({addressFormat, entropy}) => {
+	const mnemonic = bip39.generateMnemonic(entropy);
 	const seed = bip39.mnemonicToSeedSync(mnemonic);
 
 	const node = bitcoin.bip32.fromSeed(seed);

src/key-formats/xpub.js

@@ -1,15 +1,15 @@
 const bitcoin = require('bitcoinjs-lib');
 
-const generateXpubKey = ({options, attempts}) => {
+const generateXpubKey = ({attempts, xpub}) => {
 	const change = 0;
 	const index = attempts - 1;
 	const derivationPath = `${change}/${index}`;
 
-	const node = bitcoin.bip32.fromBase58(options.xpub);
+	const node = bitcoin.bip32.fromBase58(xpub);
 	const {publicKey} = node.derivePath(derivationPath);
 
 	const format = () => ({
-		xpub: options.xpub,
+		xpub,
 		derivationPath
 	});