Update Fixer.io Auth to apiKey

README.md

@@ -183,7 +183,7 @@ API | Description | Auth | HTTPS | CORS | Link |
 | Currencylayer | Exchange rates and currency conversion | `apiKey` | Yes | Unknown | [Go!](https://currencylayer.com/documentation) |
 | Czech National Bank | A collection of exchange rates | No | Yes | Unknown | [Go!](https://www.cnb.cz/cs/financni_trhy/devizovy_trh/kurzy_devizoveho_trhu/denni_kurz.xml) |
 | Exchangeratesapi.io | Exchange rates with currency conversion | No | Yes | Yes | [Go!](https://exchangeratesapi.io) |
-| Fixer.io | Exchange rates and currency conversion | No | Yes | Unknown | [Go!](http://fixer.io) |
+| Fixer.io | Exchange rates and currency conversion | `apiKey` | Yes | Unknown | [Go!](http://fixer.io) |
 | LabStack | Accurate and reliable live currency exchange rates for over 150 symbols | `apiKey` | Yes | Yes | [Go!](https://labstack.com/docs/api/currency) |
 
 ### Data Validation