Update README.md

Adds Soundcloud and Mixcloud to music cat

README.md

@@ -49,6 +49,8 @@ A collective list of JSON APIs for use in web development.
 | Discogs | Music | No | [Go!](https://www.discogs.com/developers/) |
 | EchoNest | Music | No | [Go!](http://developer.echonest.com/docs/v4) |
 | LastFm | Music | No | [Go!](http://www.last.fm/api) |
+| Mixcloud | Music | No | [Go!](https://www.mixcloud.com/developers/) |
+| Soundcloud | Music | No | [Go!](https://developers.soundcloud.com/) |
 | Spotify | Music | No | [Go!](https://developer.spotify.com/web-api/migration-guide/) |
 
 ### Science