Log miner fee (#237)

* Get miner fee written in some wallet plugins

* Return txid and fee for geth. possible problem with txid (zero hash on pending transaction)

* bitgo fee return

* Wallet apis fees save in cryptoAtoms

lib/plugins/wallet/geth/base.js

@@ -6,6 +6,7 @@ const hdkey = require('ethereumjs-wallet/hdkey')
 const Tx = require('ethereumjs-tx')
 const util = require('ethereumjs-util')
 const pify = require('pify')
+const BN = require('../../../bn')
 
 const NAME = 'geth'
 exports.SUPPORTED_MODULES = ['wallet']
@@ -47,6 +48,16 @@ function isStrictAddress (cryptoCode, toAddress) {
 function sendCoins (account, toAddress, cryptoAtoms, cryptoCode) {
   return generateTx(toAddress, defaultWallet(account), cryptoAtoms, false)
     .then(pify(web3.eth.sendRawTransaction))
+    .then(r => {
+      return pify(web3.eth.getTransactionByHash)(r.result)
+        .then(tx => {
+          if (!tx) return { txid: r.result }
+
+          const fee = BN(tx.gas).multipliedBy(BN(tx.gasPrice)).round()
+
+          return { txid: r.result, fee }
+        })
+    })
 }
 
 function checkCryptoCode (cryptoCode) {