Update README.md

README.md

+install ros: http://wiki.ros.org/kinetic/Installation/Ubuntu
+install Unity3D for linux: https://forum.unity.com/threads/unity-on-linux-release-notes-and-known-issues.350256/page-2 => 2018.3
+------------------------------------------------------------------
+setup a crowdbot catkin workspace: http://wiki.ros.org/catkin/Tutorials/create_a_workspace
+------------------------------------------------------------------
+install rosbridge
+------------------------------------------------------------------
 CrowdMP is a shared unity set of projects to create and run experiment with all  
 sort of crowds.  
 It is composed of: