Added Stattleship

Stattleship is a sports-centric API offering all 4 major U.S. sports

README.md

@@ -144,6 +144,7 @@ A collective list of JSON APIs for use in web development.
 |---|---|---|---|
 | Football-Data.org | Football Data | No | [Go!](http://api.football-data.org) |
 | FitBit | FitBit API | No | [Go!](https://dev.fitbit.com) |
+| Stattleship | MLB, NBA, NHL, NFL | No | [Go!](https://www.stattleship.com/#) |
 
 ### Transportation
 | API | Description | OAuth |Link |