docs(readme): add note about not supporting Node.js 7
@@ -91,6 +91,8 @@ sudo zypper in mraa
Installing for Node.js only
---------------------------
+> Note: Node.js 7.0.0+ is not supported. You'll have to downgrade to 6.x.x.
+
You can also install just the node.js mraa module by using npm. You will need a
C++ compiler and the node development headers, however it's not required to
have SWIG installed.
