Add IEX for Finance API

README.md

@@ -218,6 +218,7 @@ API | Description | Auth | HTTPS | Link |
 | Barchart OnDemand | Stock, Futures, and Forex Market Data | `apiKey` | Yes | [Go!](https://www.barchartondemand.com/free) |
 | CoinDesk | Bitcoin Price Index | No | No | [Go!](http://www.coindesk.com/api/) |
 | Consumer Financial Protection Bureau | Financial services consumer complains data | `apiKey` | Yes | [Go!](https://data.consumerfinance.gov/resource/jhzv-w97w.json) |
+| IEX | Stocks and Market Data | No | Yes| [Go!](https://iextrading.com/developer/) |
 | Razorpay IFSC | Indian Financial Systems Code (Bank Branch Codes) | No | Yes | [Go!](https://ifsc.razorpay.com/) |
 
 ### Food & Drink