fixed typo in README.md

README.md

 # cv201718_assignments
 
-This repository hold all assignments for the class "Computer Vision" in the winter term 2017/2018 at Institute for Computer Science, Freie Universität Berlin.
+This repository holds all assignments for the class "Computer Vision" in the winter term 2017/2018 at Institute for Computer Science, Freie Universität Berlin.