Update ReadMe.md

ReadMe.md

@@ -28,7 +28,7 @@ You can also build PolyFit from the source code:
 * Clone the repository or download the [source code](https://github.com/LiangliangNan/PolyFit).
 * Dependencies
   - [Qt5](https://www.qt.io/) (v5.12.12, v5.10.1, v5.9.2, and v5.8.0 were tested). Qt is required by the [GUI demo](./code/PolyFit). You should still be able to build the [command-line example](./Example) without Qt. 
-  - [CGAL](http://www.cgal.org/index.html) (v5.5, v5.0, v4.11.1, and v4.10 were tested).
+  - [CGAL](http://www.cgal.org/index.html) (v6.0, v5.5, v5.0, v4.11.1, and v4.10 were tested).
 
 * Build PolyFit