Add QuadrigaCX exchange and ticker (#176)

* Add QuadrigaCX exchange and ticker

* Clean up code from QuadrigaCX

lib/plugins/exchange/quadrigacx/quadrigacx.js

@@ -0,0 +1,28 @@
+const common = require('../../common/quadrigacx')
+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 trade (type, account, cryptoAtoms, fiatCode, cryptoCode) {
+  return Promise.resolve()
+  .then(() => {
+    const market = common.buildMarket(fiatCode, cryptoCode)
+    const options = {
+      book: market,
+      amount: coinUtils.toUnit(cryptoAtoms, cryptoCode).toFixed(8)
+    }
+    
+    return common.authRequest(account, '/' + type, options)
+  })
+}
+
+module.exports = {
+  buy,
+  sell
+}