feat: add transaction batching module

feat: plugin sendCoins batching support
feat: batching processing on poller
feat: mock-wallet batching
fix: bitcoin tx batching
fix: transaction batching db table

lib/plugins/wallet/mock-wallet/mock-wallet.js

@@ -1,3 +1,5 @@
+const _ = require('lodash/fp')
+
 const BN = require('../../../bn')
 const E = require('../../../error')
 const { utils: coinUtils } = require('lamassu-coins')
@@ -57,7 +59,29 @@ function sendCoins (account, tx, settings, operatorId) {
   })
 }
 
+<<<<<<< HEAD
 function newAddress (account, info, tx, settings, operatorId) {
+=======
+function sendCoinsBatch (account, txs, cryptoCode) {
+  sendCount = sendCount + txs.length
+  return new Promise((resolve, reject) => {
+    setTimeout(() => {
+      const cryptoSum = _.reduce((acc, value) => acc.add(value.crypto_atoms), BN(0), txs)
+      if (isInsufficient(cryptoSum, cryptoCode)) {
+        console.log('[%s] DEBUG: Mock wallet insufficient funds: %s',
+          cryptoCode, cryptoSum.toString())
+        return reject(new E.InsufficientFundsError())
+      }
+
+      console.log('[%s] DEBUG: Mock wallet sending %s cryptoAtoms in a batch',
+        cryptoCode, cryptoSum.toString())
+      return resolve({ txid: '<txHash>', fee: BN(0) })
+    }, 2000)
+  })
+}
+
+function newAddress () {
+>>>>>>> feat: add transaction batching module
   t0 = Date.now()
   return Promise.resolve('<Fake address, don\'t send>')
 }
@@ -93,6 +117,7 @@ function getStatus (account, tx, requested, settings, operatorId) {
 module.exports = {
   NAME,
   balance,
+  sendCoinsBatch,
   sendCoins,
   newAddress,
   getStatus,