Fix README homebrew install regarding glfw3

servo · oksome · Nov 5, 2014 · Nov 5, 2014 · b01c0004fabfcb7f161eef6f8fe2824af5caeb71
commit b01c0004fabfcb7f161eef6f8fe2824af5caeb71
diff --git a/README.md b/README.md
@@ -16,6 +16,7 @@ script](etc/ci/travis.install.sh).
 On OS X (homebrew):
 
 ``` sh
+brew tap homebrew/versions
 brew install automake pkg-config python glfw3 cmake
 pip install virtualenv
 ```