Adding memory leak check option to tests.

README.md

@@ -7,4 +7,12 @@ In the ```rive``` directory, run ```build.sh``` to debug build and ```build.sh r
 ## Testing
 In the ```dev``` directory, run ```test.sh``` to compile and execute the tests.
 
-The tests live in ```rive/test```. To add new tests, create a new ```xxx_test.cpp``` file here. The test harness will automatically pick up the new file.
+The tests live in ```rive/test```. To add new tests, create a new ```xxx_test.cpp``` file here. The test harness will automatically pick up the new file.
+
+## Memory Checks
+Note that if you're on MacOS you'll want to install valgrind, which is somewhat complicated these days. This is the easiest solution (please PR a better one when it becomes available).
+```
+brew tap LouisBrunner/valgrind
+brew install --HEAD LouisBrunner/valgrind/valgrind
+```
+You can now run the all the tests through valgrind by running ```test.sh memory```.