Add codecov.io badge
diff --git a/README b/README
index 55775c8..e50f8f0 100644
--- a/README
+++ b/README
@@ -1,9 +1,10 @@
-[](https://travis-ci.org/harfbuzz/harfbuzz)
-[](https://ci.appveyor.com/project/harfbuzz/harfbuzz)
-[](https://circleci.com/gh/harfbuzz/harfbuzz)
-[](https://scan.coverity.com/projects/behdad-harfbuzz)
-[](https://app.codacy.com/app/behdad/harfbuzz)
-[](https://coveralls.io/r/harfbuzz/harfbuzz)
+[](https://travis-ci.org/harfbuzz/harfbuzz)
+[](https://ci.appveyor.com/project/harfbuzz/harfbuzz)
+[](https://circleci.com/gh/harfbuzz/harfbuzz)
+[](https://scan.coverity.com/projects/behdad-harfbuzz)
+[](https://app.codacy.com/app/behdad/harfbuzz)
+[](https://codecov.io/gh/harfbuzz/harfbuzz)
+[](https://coveralls.io/r/harfbuzz/harfbuzz)
[ABI Tracker](http://abi-laboratory.pro/tracker/timeline/harfbuzz/)
This is HarfBuzz, a text shaping library.