Merge pull request #533 from karllhughes/patch-1

Adding another free stock data API

README.md

@@ -247,6 +247,7 @@ API | Description | Auth | HTTPS | Link |
 ### Finance
 API | Description | Auth | HTTPS | Link |
 |---|---|---|---|---|
+| Alpha Vantage | Realtime and historical stock data | `apiKey` | Yes | [Go!](https://www.alphavantage.co/) |
 | Barchart OnDemand | Stock, Futures, and Forex Market Data | `apiKey` | Yes | [Go!](https://www.barchartondemand.com/free) |
 | 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/) |