Naming testling-ci URLs in README

README.md

@@ -8,7 +8,7 @@
 
 [![npm badge][11]][npm-url]
 
-[![browser support][9]][10]
+[![browser support][testling-png]][testling-url]
 
 Given two valid integers in string form, return the smaller of the two.
 
@@ -42,8 +42,8 @@ Simply clone the repo, run `npm install`, and then run `npm test`.
 [deps-url]: https://david-dm.org/ljharb/big-integer-min
 [dev-deps-svg]: https://david-dm.org/ljharb/big-integer-min/dev-status.svg
 [dev-deps-url]: https://david-dm.org/ljharb/big-integer-min#info=devDependencies
-[9]: https://ci.testling.com/ljharb/big-integer-min.png
-[10]: https://ci.testling.com/ljharb/big-integer-min
+[testling-png]: https://ci.testling.com/ljharb/big-integer-min.png
+[testling-url]: https://ci.testling.com/ljharb/big-integer-min
 [11]: https://nodei.co/npm/big-integer-min.png?downloads=true&stars=true
 [license-image]: http://img.shields.io/npm/l/big-integer-min.svg
 [license-url]: LICENSE