Refactored some exchange code

lib/plugins/exchange/bitstamp/bitstamp.js

@@ -1,45 +0,0 @@
-const common = require('../../common/bitstamp')
-const coinUtils = require('../../../coin-utils')
-
-function buy (account, cryptoAtoms, fiatCode, cryptoCode) {
-  return trade('buy', account, cryptoAtoms, fiatCode, cryptoCode)
-}
-
-function sell (account, cryptoAtoms, fiatCode, cryptoCode) {
-  return trade('sell', account, cryptoAtoms, fiatCode, cryptoCode)
-}
-
-function handleErrors (data) {
-  if (!data.reason || !data.reason.__all__) return data
-
-  const err = new Error(data.reason.__all__[0])
-
-  if (data.reason.__all__[0].indexOf('Minimum order size is') === 0) {
-    err.name = 'orderTooSmall'
-  }
-
-  throw err
-}
-
-function trade (type, account, cryptoAtoms, _fiatCode, cryptoCode) {
-  const fiatCode = _fiatCode === 'USD' ? 'USD' : 'EUR'
-
-  try {
-    const market = common.buildMarket(fiatCode, cryptoCode)
-    const options = {amount: coinUtils.toUnit(cryptoAtoms, cryptoCode).toFixed(8)}
-
-    return common.authRequest(account, '/' + type + '/market/' + market, options)
-      .catch(e => {
-        if (e.response) handleErrors(e.response.data)
-        throw e
-      })
-      .then(handleErrors)
-  } catch (e) {
-    return Promise.reject(e)
-  }
-}
-
-module.exports = {
-  buy,
-  sell
-}