Update LCOV link (#446)

README.md

diff --git a/README.md b/README.md
index 90d15c7..45abf84 100644
--- a/README.md
+++ b/README.md
@@ -9,7 +9,7 @@
 
 `collect_coverage` collects coverage JSON from the Dart VM Service.
 `format_coverage` formats JSON coverage data into either
-[LCOV](http://ltp.sourceforge.net/coverage/lcov.php) or pretty-printed format.
+[LCOV](https://github.com/linux-test-project/lcov) or pretty-printed format.
 
 #### Install coverage