Patch robotwebtools link (#1080)

* robot web tools link in README was broken

* Update README.md

README.md

@@ -170,9 +170,9 @@ A big ***Thank you!*** to everyone that have helped make this extension better!
 * PickNikRobotics ([@PickNikRobotics](https://github.com/PickNikRobotics)) for code formatting
 
 ### ROS Web Tools
-This extension leverages [ROS Web Tools](http://robotwebtools.org/) for URDF Previewing.
+This extension leverages [ROS Web Tools](http://robotwebtools.github.io/) for URDF Previewing.
 
-*Russell Toris, Julius Kammerl, David Lu, Jihoon Lee, Odest Chadwicke Jenkins, Sarah Osentoski, Mitchell Wills, and Sonia Chernova. [Robot Web Tools: Efficient Messaging for Cloud Robotics](http://robotwebtools.org/pdf/paper.pdf). In Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2015*
+*Russell Toris, Julius Kammerl, David Lu, Jihoon Lee, Odest Chadwicke Jenkins, Sarah Osentoski, Mitchell Wills, and Sonia Chernova. [Robot Web Tools: Efficient Messaging for Cloud Robotics](http://robotwebtools.github.io/pdf/paper.pdf). In Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2015*
 
 
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